Coomber v Simon Blackwood (Workers' Compensation Regulator) [2016] QIRC 33

QUEENSLAND INDUSTRIAL RELATIONS COMMISSION CITATION: Coomber v Simon Blackwood (Workers' Compensation Regulator) [2016] QIRC 033 PARTIES: Coomber, John Laurence (Appellant) v Simon Blackwood (Workers' Compensation Regulator) (Respondent) CASE NO: WC/2014/6 PROCEEDING: Appeal against decision of the Workers' Compensation Regulator DELIVERED ON: 15 March 2016 HEARING DATES: HEARD AT: 16, 17 July 2014, 23 October 2014 Brisbane MEMBER: Industrial Commissioner Neate ORDERS: 1. The appeal is allowed. 2. The decision of the Workers' Compensation Regulator is set aside and substituted with a decision that the claim for compensation is one for acceptance. 3. The Respondent is to pay the Appellant's costs of and incidental to the appeal to be agreed or, failing agreement, to be subject of a further application to the Commission. CATCHWORDS: WORKERS' COMPENSATION - APPEAL AGAINST DECISION - whether Appellant suffered an "injury" - nature of the injury - aggravation of existing injury - whether injury arose out of, or in the course of, employment - whether employment was a significant contributing factor - appellant bears onus of proof CASES: Workers' Compensation and Rehabilitation Act 2003 s 32 Coombes v Q-Comp (2007) 185 QGIG 331 Fielder v WorkCover Queensland (2004) 175 QGIG 871 -- 1 of 34 -- 2 MacArthur v WorkCover Queensland (2001) 167 QGIG 100 Nilsson v Q-Comp (2008) 189 QGIG 523 Pollock v Wellington (1996) 15 WAR 1 Q-COMP v Parsons (2007) 185 QGIG 1 R v Turner [1975] QB 834 Rossmuller v Q-Comp C/2009/36 - decision http://www.qirc.qld.gov.au Toll Holdings Ltd v Q-Comp QC/2011/121 - decision http://www.qirc.qld.gov.au APPEARANCES: Mr B. du Plessis, counsel for the Appellant instructed by Shine Lawyers Mr C. Clark, counsel instructed directly by the Respondent Decision [1] This is an appeal by John Laurence Coomber ("the Appellant") under the Workers' Compensation and Rehabilitation Act 2003 ("the Act") against a decision of the Workers' Compensation Regulator's Review Unit ("the Respondent") dated 12 December 2013. That decision confirmed the decision of WorkCover Queensland dated 13 September 2013 to reject his application for compensation in respect of an injury to his lower spine and his sacroiliac joints, which he claims he suffered in the course of his employment as a bus driver. Issues for determination [2] Broadly speaking, the issue for determination in this appeal is whether the Appellant sustained an "injury" within the meaning of that term in s 32 of the Act. In particular the Commission must decide whether, as a result of an incident while he was driving a bus on 23 August 2013, the Appellant suffered an aggravation of his pre-existing degenerative back condition. [3] At the relevant time, s 32 provided: "32 Meaning of injury (1) An injury is personal injury arising out of, or in the course of, employment if the employment is a significant contributing factor to the injury. … (3) Injury includes the following - … (b) an aggravation of the following, if the aggravation arises out of, or in the course of, employment and the employment is a significant contributing factor the aggravation - (i) a personal injury; -- 2 of 34 -- 3 (ii) a disease; (iii) a medical condition if the condition becomes a personal injury or disease because of the aggravation; …" [4] There is no issue that the Appellant was a "worker" within the meaning of the Act. [5] The Appellant bears the onus of proof.1 To succeed in his appeal he must satisfy the Commission on the balance of probabilities that: (a) he suffered a personal injury; (b) the injury arose out of, or in the course of, his employment; and (c) his employment was a significant contributing factor to the injury. [6] The Appellant submits that the resolution of this appeal involves determination of the following issues: (a) as a matter of fact, what actually occurred in the course of the Appellant's employment in relation to the event on 23 August 2013 he alleges caused the injury to his back; (b) on the basis of what was found to have occurred, has the Appellant proven that: a. his injury is one arising out of, or in the course of, employment; and b. he sustained an "injury" to which employment was a significant contributing factor. [7] In the Respondent's submission, the issues in this appeal are: (a) what was the precise injury suffered by the Appellant in the course of the alleged incident on 23 August 2013; and (b) whether the Appellant's work duties amounted to "a significant contributing factor" to any alleged injury. [8] As will become apparent from the evidence in relation to the appeal, and by reference to the statutory criteria and the issues identified by each party, it is necessary to decide: (a) the circumstances in which the alleged injury occurred (and hence whether his injury arose out of, or in the course of, his employment); (b) whether the Appellant suffered an injury; and (c) if so whether the Appellant's employment was a significant contributing factor to the injury. 1 See e.g. Rossmuller v Q-Comp C/2009/36, [2]; Toll Holdings Ltd v Q-Comp QC/2011/121 - Decision http://www.qirc.qld.gov.au, [5]. -- 3 of 34 -- 4 Background to the incident [9] The Appellant was employed from October 2005 by Surfside Buslines as a bus driver. Before considering the incident on 23 August 2013 as a result of which the Appellant claims to have suffered an injury, and actions taken subsequently, it is necessary to set out the evidence in relation to: (a) the features of the driver's seat on which the Appellant was sitting at the time of the alleged incident; and (b) events on 22 August 2013 which preceded, and have some bearing on, that incident. [10] Some features of the bus driver's seat: The Appellant and three other witnesses gave evidence about the driver's seat, primarily in relation to the types and characteristics of different settings on it. [11] The Appellant gave evidence that the bus he was driving on relevant dates (bus 334) was fitted with an ISRI 6860/875 NTS seat (see photographs Exhibit 1), which he described as "a very comfortable seat when working properly." Below the level of the seat and at one side are buttons including button 3 which controls the "hard" and "soft" settings: (a) the "hard" setting is when the button is fully down, the seat is supported by compressed air and is extremely comfortable; and (b) the "soft" setting is when the button is in the upper position, the seat goes to a very "soft" setting which the Appellant described as "equivalent to sitting on a spring, bouncing up and down on a spring or even an exercise ball" (a setting which he said he did not use when the hard setting was serviceable "due to its flexibility"). The Appellant said the settings were distinct and there was no graduated setting. A driver could choose the setting which was more comfortable. [12] According to the Appellant, there is some play or absorption in a seat on the hard setting when the weight of the driver is on it. If the bus were to hit a corrugation, hole or bump in the road, there is a "minimal force on the driver and it is very comfortable." When the seat is broken, there is, the Appellant said, "a play in the top of the seat which whiplashes your back on corrugations and bumpy roads." [13] The Appellant gave evidence that if the bus were to hit a bump when the seat is on the soft setting, the seat "will throw you up and down and if the bump is a good sort of bump, like a speed hump or a hole in the road, it will slam you into the bottom of the floor." The Appellant described it as being "sort of like a spring that can go right to the bottom." If the bus goes over any corrugation, "the seat becomes very violent with you and that's why hardly anybody uses that the soft setting, because it's too violent and in my case, it just bottoms straight-out". In other words, although the seat is padded, "when it hits the bottom, it is like hitting a lump of cement, really." -- 4 of 34 -- 5 [14] In cross-examination, the Appellant said that the seat "Throws you straight up … then jerks you back again." He added that when someone sits on it, the seat will go down with the person's weight. When the bus hits a bump, the seat goes up to its original position and "the plane area would flick your back. It would jerk your back rather violently." [15] According to the Appellant, the seat has capacity to support people whose weights range from 50 kilograms to 150 kilograms. At the time of the incident, the Appellant weighed approximately 80 kilograms. [16] The Appellant described the process of starting the engine of a bus and waiting for sufficient air pressure to build up under the seat to operate the shock absorber. At that point the driver can test the seat to assess whether it is operational. If the seat is on the hard setting it cannot be pushed down by hand. If the hard setting is defective, the seat can be pushed down by hand about two inches. The Appellant gave evidence that he tested the seat each and every day while he was working because the seats tended to be broken by heavier drivers. He had found "quite a few" defective seats during his eight years at Surfside Buslines. Although he had complained about those seats, not all were repaired when he reported them. [17] Graham Johnson, another bus driver at Surfside Buslines, also gave evidence about the settings on the driver's seats installed in the relevant type of bus. According to Mr Johnson: (a) when a seat is locked into the hard setting the seat does not move but has a damper effect by absorbing the driver's weight without moving up and down; (b) the soft ride setting allows a seat to move up and down as the bus is riding along over bumpy roads. [18] Mr Johnson described a defective seats in the hard position as having some "free play" such that the seat will "freely move up and down on its own by a few mils." A seat can be tested before the bus is taken out on the road. Mr Johnson weighs about 93 kilograms. He tests the seat by sitting on it and putting his hands under it and lifting his knees to see if there is any movement. [19] Mr Johnson also gave evidence that he had complained about defective driver's seats on buses on possibly six to a dozen times over a period of about seven years. Three documented examples of his reports about seats he considered defective were in evidence (see Exhibit 13). Mr Johnson also provided video recordings that he had made on a smart phone of what he described as defective seats on five dates between 2 August 2013 and 3 June 2014. He said that they showed excessive movement of a few millimetres, or in one case free play of about one inch on the hard setting. (Exhibit 14) However he said that on one occasion, when sitting on a seat in the soft setting, he was thrown into the air "maybe a couple of inches." [20] Paul Cooper, a mechanic at Surfside Busline, gave evidence that: (a) with the hardest setting there is a "very minimal" movement and "good shock absorption;" and -- 5 of 34 -- 6 (b) with the softer setting, there is a "good springing motion" and he would "just bounce up and down." In the softer position there is more give, but he was unsure whether the seat would bottom out when going over potholes and bumps. [21] Shane Rollins is Surfside Buslines' workshop manager for the region, running three workshops including the one at the Ernest depot. He looks after the operation side of the company including employees and the servicing and maintenance of vehicles. Over some 15 years working in bus maintenance he has become aware of the mechanical workings of buses used by Surfside Buslines, including buses such as bus 334. He identified the seat in bus 334 as the type of seat that is fitted in the majority of the company's vehicles. The seat is manufactured in Germany and Mr Rollins described it as a "top of the range seat." Included in its features are a suspension system, an air system, a dampener system, and lumbar support. He described how the airbag and hydraulics in the seat work together to dampen blows, like a car suspension. [22] Mr Rollins said that the settings depend on the driver's weight and where he wants to set it for such things as the types of roads the buses travel on. The drivers employed by Surfside Buslines ranged in weight from approximately 60 kilograms to 140 kilograms plus. [23] Mr Rollins described: (a) the hard setting as being at about 70 to 80 psi of air pressure and having some slight movement, possibly an inch or an inch and a half depending on the weight put on the seat; and (b) the soft setting as enabling the seat to "move up and down freely but not enough to bottom out." That setting is mainly the airbag with not much shock absorber. However there is also a bump stop in the bottom of the airbag assembly which is a piece of rubber (like half a soccer ball) that stops the steel plate at the top banging onto a steel plate at the bottom. [24] In his opinion, a driver should not have the seat on the soft setting but should have some sort of dampener. He explained how the seat could be set between the hard and soft setting by use of a lever that controls the flow of oil to dampen the suspension of the shock absorber of the seat. All drivers would know the means of adjusting the seat suspension, as he thought it was part of the training package when drivers are first employed at Surfside Buslines. [25] He disagreed that the hard setting would catapult the driver into the air and have some sort of whiplash effect on his back, and said that he had never heard of that happening. In his opinion, the seat would not move down far enough to catapult. Once the driver's weight is on it, the seat would still only move about an inch or an inch and a half. [26] Mr Rollins expressed the view that if the seat was on a soft setting on a rough road it would move up and down but would not catapult. It would not bottom out or spring a person up because the air and the oil would stop it from catapulting. Even if there was something wrong with the seat mechanism, it would require pressure going up to -- 6 of 34 -- 7 catapult somebody. It would need some sort of spring mechanism to catapult a person in a quick sort of manner. [27] Mr Rollins said that a defective seat would be reported about once each week, but "I'm not saying there is anything wrong with that seat." He viewed the video images of defective drivers' seats recorded by Mr Johnson on his smart phone (Exhibit 14). He observed that: (a) in relation to the first video, the movement of the seat was demonstrated by shaking it from somewhere fairly high up the back of the seat. That was not a legitimate test as it operated like a lever and obtained a lot of movement, including in the seat. It was difficult to ascertain from the video whether the seat had air or whether the second lever (which is the dampener) had been activated. The seat appeared to be bottomed out with no air, which is the position if the bus is not running. He was not able to see the force that was being applied to the top of the seat. In any case, Mr Rollins did not detect any genuine defect; (b) in relation to the second video, the dampener switch was not activated but was in the off position and all that seemed to be moving was a plastic guard on either side of the seat; (c) in relation to third video, Mr Rollins observed the plastic guard moving but no dampener on the second lever and the seat lifted about an inch. He observed no discernible genuine defect and noted that he could not see whether the bus was running and there was any air in the seat system. Although the air button was activated, the seat has to have movement up and down. He observed no defect in relation to the other two seats in separate video recordings. [28] Findings: Having regard to the evidence as a whole, and the experience and qualifications of the witnesses, I find that: (a) when a driver's seat is in the hard setting, there is some play or absorption (about one inch), and the extent to which a seat moves up and down will be affected by the weight of the person sitting on it; (b) generally speaking, the hard setting is the preferred setting for normal driving conditions; (c) a properly functioning seat on the hard setting would not catapult a driver upwards from the seat; (d) there is substantially more variation in movement up and down when a driver is sitting on a seat on the soft setting; (e) a person sitting on a seat on the soft setting would experience an up and down springing motion but not enough for the seat to bottom out or to catapult the person out of the seat; -- 7 of 34 -- 8 (f) generally speaking, the soft setting is not, and should not be, used for usual road conditions; and (g) the Appellant did not usually use the soft setting because of its flexibility. [29] Events on 22 August 2013: In August 2013, the Appellant was working on nine days each fortnight, driving the same route but on different shifts from day to day. His assigned route was 3040, which started and ended at Pacific Fair and was mainly along a highway. [30] The Appellant gave evidence that, on 22 August 2013, he was allocated bus 334. The timetable for route 3040 that day commenced at 7.40 am and concluded at 5.40 pm. He went through the start-up procedure, checked his bus for any damage, filled out the daily inspection report and waited for the air to build up. When he drove the bus away from the Ernest depot, the bus hit a bump. According to the Appellant, "the seat whiplashed my back and threw me up, so I realised that the seat was broken in the hard setting." He also stated "It was a catapult. It was back to the original position and then the plane threw me up from there." The distance upwards was "only two inches, roughly" but it "plays havoc with your back." He described his back as "pretty sensitive. Very sensitive to these things." [31] The Appellant changed the seat to the softer setting and finished his 10 hour shift on that setting. On his return to the depot, he dictated a defect report so that the workshop would fix the seat. The Work Order included: "Seating, Drivers Seat issue: shock absorber needs replacing. When it is on the hardest setting the seat catapults upwards over bumps and jerks the drivers backs." (Exhibit 2) The Appellant confirmed that those were his words. [32] According to the Appellant, his back was "a little bit sore with the bouncing up and down, but I was okay. I was fine." The Appellant also said that since back surgery in August 2011, up to that point he had to been pain-free, and had no pain or discomfort in either left or right sacroiliac joint. [33] Garrick Wildman is employed as a driver by Surfside Busline. He gave evidence that on 22 August 2013 after work in the pay room he had a general conversation with others, including the Appellant, sitting around the meal room about the events of the day. He recalled the Appellant saying words to the effect that "The bus I had today was shitty and I'm going to defect it because it's hurt my back, and if I get it again I'll sue." [34] The Appellant said that he regarded Mr Wildman as a friend at the time although he had not had anything to do with Mr Wildman since the day of the incident on 23 August 2013. He strenuously denied saying to Mr Wildman that if he got that bus again he would take it out of the yard until it did his back and he would go on compo. According to the Appellant, "I would never say anything - it's not in my make up, sir. … I swear to God. … It's not in my make up, and I'm under oath." -- 8 of 34 -- 9 [35] Mr Cooper gave evidence that complaints about defective vehicles only come to the workshop via the computer and appear on a screen in the workshop. He was the person responsible for repairing bus 334 on 22 August 2013. His initials appear on the Work Order (Exhibit 2), which indicates that the testing occurred between 7.01 and 7.16 pm. He wrote: "test function of seat, fully functional with no defect to the seat shock absorber." Although he did not specifically recall doing this job, he described the process he would have undertaken to check the seat (including sitting on it and bouncing up and down to test the different settings). Mr Cooper weighs 90 kilograms, i.e., more than the Appellant. He agreed that he tested the function of the seat and found it fully functional with no defect to the seat shock absorber. [36] Mr Cooper said that: (a) about one or two bus seats are reported as defective each week; (b) he had never known any seat to catapult up with a shock absorber; (c) it was "impossible" that the Appellant found the seat was still defective on 23 August 2013 - unless somebody had tampered with it that night which, Mr Cooper said was "highly unlikely." [37] Observations: At this stage I make the two observations, rather than findings. First, on the Appellant's evidence, the amount that the seat moved upwards in response to the bus hitting a bump was about two inches. That is at the upper limit of the range of give on a seat in working order on the hard setting. There is no evidence to suggest that a seat could project itself upwards beyond its original setting. In other words, the most it might rise would be from the lower position when it bore the driver's weight to the position at rest without any object on it. The mechanism of the seat is such that it would not "catapult" a driver, in the sense of "fling forcibly"2 or "hurl."3 It might be that the Appellant bounced a little above the level of the seat, and that he felt the impact of the jolt more keenly because of his "pretty sensitive" back, and hence considered the seat to be defective. [38] Second, there was evidence that Surfside Buslines had about 300 buses and it was rare, though not unknown, for a driver to be allocated the same bus on two or more occasions, particularly on consecutive days. Consequently, even if the Appellant made statements along the lines suggested by Mr Wildman (which the Appellant denies), those statements could be characterised as expressions of frustration or irritation at the past and supposed future effects on the Appellant's "pretty sensitive" back of what he considered to be a defective bus seat. He could not have anticipated with confidence, let alone certainty, that he would be allocated the same bus on the following day. Hence he could not have been indicating that he had contrived some scheme to extract compensation. The incident on 23 August 2013 [39] The Appellant's account: On Friday, 23 August 2013, the Appellant attended the depot at 7.00 am and started bus 334 after 7.20 am. In the Appellant's experience over eight years he had never been assigned the same bus twice. He remembered thinking 2 The Australian Concise Oxford Dictionary of Current English, 7th ed, Oxford University Press, 1987, 157 3 Macquarie Dictionary, 5th edn, 2009, 273. -- 9 of 34 -- 10 that, as he had defected the seat the night before, he expected that it "should be fixed." He inspected the bus. Once the air pressures had been built up, he checked to see if the seat had been repaired. There was "a play in the top of the seat where you could push - put your hand on the seat and depress the seat which you shouldn't be able to do. It just had free play in it, about 2 inches, so that indicated to me that the shock absorber under the seat was broken - was still broken." In other words, it was in the same condition as it had been the previous day. In the Appellant's opinion, that rendered the seat unusable in the hard setting. [40] According to the Appellant, he completed, but did not sign, a Record of Daily Inspection of bus 334 for route 3047s. That type of form is meant to be completed before a driver leaves the yard, and is handed in at the end of the shift. The document (Exhibit 4) shows that the Appellant checked and ticked all the specified items and added in his own handwriting "DRIVERS SEAT X", and indicated on diagrams where there were markings on the sides of the bus. Although he could not be sure why he did not sign the form, he speculated that it was because he realised that the seat was broken and he took the bus to the workshop. At that point he was not certain whether he would take this bus. [41] The Appellant stated that he drove the bus to the workshop and parked outside where there was a mechanic waiting. The Appellant explained that he had defected the bus the previous night for a broken driver's seat and that the seat had not been fixed. When the Appellant asked mechanic to check the seat, the mechanic "went off his head" at the Appellant. According to the Appellant, the mechanic said the Appellant should take the bus and the mechanic would sort out what had happened. At that stage, the Appellant considered that he "had no other choice but to take the bus" because directives from mechanics and operations management were not to be questioned. He did not report the defective seat to anybody else, including the mechanic. Rather, he drove the seat on the soft setting as he had done on the previous day. [42] The Appellant said that he drove bus 334 along route 3047s, which included a school run. He commenced at 8.02 am for a shift that was scheduled to end at 5.22 pm (see Exhibit 3). Having been to Southport Primary School he parked in Scarborough Street facing southbound outside the Gold Coast TAFE in Southport, and took on board passengers to drive from Southport Australia Fair as scheduled at 8.35 am. He drove the bus across the intersection of Scarborough Street and Nerang Street. According to the Appellant: "This road is extremely narrow. You can only just fit your bus on to it … Due to the road works. … they were working on the inside of the road so the road was very, very narrow. It was a large pothole … outside the Lucky 7." (T1:34) Scarborough Street is very busy at that time of day. The Appellant estimated that the bus was travelling at about 20 kilometres per hour. [43] The bus had suspension. The Appellant's seat was on the soft setting. He was wearing a seatbelt. The front left wheel of the bus struck the pothole. According to the Appellant, "the seat went down, up and slammed me into the floor, thus injuring my back." He continued, "the front left-hand wheel went down the hole and forced the seat to slam me into the floor so - on the soft setting. Yes, it was very painful." The Appellant explained: -- 10 of 34 -- 11 "the soft setting is like a very bouncy spring, and there is no real absorption on that seat, so hitting something really hard will bottom the seat out, and that's what I mean. When I hit that pothole, the seat threw me up and bottomed the whole seat out quite hard." (T1:35) [44] The location of the incident is indicated on a map (Exhibit 5) with an "x" by reference to "POT HOLE (LARGE)" and more specifically on a hand drawn plan prepared by the Appellant (Exhibit 6) which indicates the location of "HOLE IN ROAD." [45] The Appellant described his pain as "horrific." Both his legs "went cold - extremely cold," he had tingling in the upper parts of his legs and buttocks and his back pain across his lower back was "just unbearable." [46] According to the Appellant, there was nowhere to pull over. He could not block any traffic, so continued "very, very slowly." In cross-examination, however, the Appellant agreed that he was stopping at bus stops all the time and there were numerous places where he could have pulled over. For example, the next bus stop in Scarborough Street after the pothole was possibly 600 metres away. He stopped there to pick up passengers. [47] Although he had scheduled breaks between runs and was apparently in great pain, the Appellant said that he did not make calls to tell people about his problem because runs are never completed on time and once passengers are offloaded, a driver has to change his computer and signs and load passengers in order to leave on schedule for the next run the. Although he was in "horrific pain all the way, right the way through from 8.35," he was also "giving myself a little bit of time to see if I repaired." He agreed that he had not repaired by lunchtime, and conceded that he might not have been in a fit state to drive the bus safely at that point. [48] Mr Browne's account: Colin Browne is an operation supervisor at the Ernest depot. His work involves the everyday running of vehicles on the road, making sure buses are correct and not defective before they leave the depot, and dealing with any maintenance breakdowns, emergencies or other incidents on the road. [49] He recalled having a conversation over the radio with the Appellant on 23 August 2013 at the start of his shift, before the Appellant left the depot, at around 7.30 to 7.40 am. The Appellant asked him whether the bus had been defected and Mr Browne said he would check. Having checked the computer system, he advised the Appellant that the bus was "good to go." There was no defect on the bus. The Appellant replied that the bus was defected the previous day and he would be defecting it at the end of his shift on return to base. Mr Browne said "Okay. Fine." [50] Mr Browne explained that the computer system provided information for that day. If the bus had been defected, it could not go on to the shift. If someone tries to enter a defected bus onto a shift, the computer rejects that and advises that the bus is defected and cannot be entered. If the bus had been defected, it could not have been allocated to any driver. However, if the bus had been checked and cleared by the workshop, it would be in the pool of allocated buses. Mr Browne also explained that he did not think it necessary to check with the workshop whether the bus had been repaired -- 11 of 34 -- 12 because: "I'm not to question workshop's judgment. Workshop make the call. They check the buses. My job is dispatch clerk supervisor." [51] The Appellant denied "categorically" the suggestion that, before he left the depot, he asked Mr Browne whether the bus had been defected. That suggestion was "totally incorrect" for that time. As noted below, the Appellant said that the conversation took place after 9.00 am. [52] On 26 August 2013, Mr Browne sent an email to his direct manager, Bryan Patten, about "john comber shift 3047 bus 334" the (Exhibit 15). That email was prepared at Mr Patten's request, apparently because Mr Browne was told that the Appellant might be making a complaint. The email set out Mr Browne's account of a conversation with the Appellant before he departed the depot at the start of his shift, and the subsequent conversations and events that day. [53] Mr Fraser's account: Malcolm Fraser is an operations controller at Surfside Buslines. He controls the drivers in the depot and allocates buses and cover shifts and make sure that drivers are on the shifts. Mr Fraser said that he had no involvement with the workshop other than defecting buses and making sure buses are cleared from the workshop. He liaises with the workshop on a daily basis for buses when there is a shortage of them, but does not check the buses. Rather he accepts that if a bus is entered on the computer system, it has been cleared from the workshop. [54] Mr Fraser recalled a conversation with the Appellant about 7.30 or 7.45 am on 23 August 2013, when the Appellant came to him at the operations window and complained about the bus that was allocated to him which he said was defected. The Appellant said that the bus was the same one that was allocated to him on the previous day and it had been defected. Mr Fraser had checked the computer system and told the Appellant that the bus had been cleared from the defect and was fine for him to take out. Mr Fraser added that if the Appellant had an issue with that bus, he could give the Appellant another one and could defect the allocated bus. The Appellant replied "no, I'll take the bus out and I'll defect it when I return." [55] According to the Appellant, he did not remember speaking to Mr Fraser before he left the depot on the morning of 23 August 2013. In particular he did not tell Mr Fraser that he had defected the bus on the previous day. Nor did Mr Fraser offered to change the bus for him. The Appellant denied "absolutely" telling Mr Fraser that he would put up with the bus that day and defect it at the end of the shift. [56] In cross-examination, Mr Fraser refuted the suggestion that the early-morning conversation was a fabrication and did not happen. [57] Mr Rollins' assessment: In Mr Rollins' opinion, a bus travelling along Scarborough Street at 20 kilometres an hour with the driver's seat in the soft setting which encounters a pothole with the left front wheel would not cause the seat to bottom out because: (a) the pothole is on the opposite side of where the driver is sitting; (b) the bus suspension would take the majority of the impact; -- 12 of 34 -- 13 (c) the seat might move a little more than two inches, but he doubted that it would move that much in the circumstances described. [58] CCTV: The Appellant gave evidence that all buses that he drove were equipped with CCTV surveillance systems which must be operational at all times. When a driver starts the engine of a bus it activates the CCTV. After a short period, a green light appears on the camera located above the driver as an indication that the CCTV is working. The Appellant did not know how to turn off the CCTV and did not know where any recording device was located. [59] Mr Browne gave evidence that 95 per cent of the buses were equipped with CCTV cameras and he thought bus 334 would have been equipped with a camera. Although he is not technically qualified, he understood that after a certain amount of time the CCTV footage would rollback and the tape would be re-used. He had no idea what happened to the CCTV footage of this bus, or whose responsibility it would be to check the CCTV footage. [60] Mr Fraser agreed that most, if not all, of the buses from the Ernest depot are equipped with CCTV monitors. If CCTV footage is required, he (or one of the other three controllers) is involved in defecting the bus for the footage to be collected by the workshop. He did not know, however, what happened to the CCTV footage of 23 August 2013. He speculated that he probably would have given an order for the footage to be downloaded once he knew that the Appellant alleged that he had been injured - "as I do with all of them." However, he could not say whether he gave such an order. Usually the footage would be brought from the workshop to the office and placed in the area where it is viewed by management staff. He had never seen any footage of the incident. Usually the health and safety manager or the operations manager would view the video footage. [61] Mr Wildman confirmed that most buses are equipped with CCTV, and that the driver has to check that the camera is on but has no control over the footage. He was aware of another incident where it was necessary to recover the CCTV footage and, although he did not know how the system worked and had not viewed the footage, he thought the footage was available within four days to a week after the incident. [62] Mr Cooper gave evidence that, while the camera is switched on, the CCTV is recording continuously. However, unless the footage is downloaded, the camera records over the previous recording after a period (possibly a week or more). The manager or someone from operations could give an order for the mechanics to download the CCTV the footage. He described the different formats for the recording of CCTV images, depending on the age of the vehicle and the equipment installed in it, but said that he does not see the footage. Rather he provides it to those who ask for it. [63] Mr Rollins agreed that all the buses are equipped with CCTV cameras and recording equipment, but was not sure what happened to the video that was taken on bus 334 on 23 August 2013. He stated that he was not in charge of defecting a bus to have the video removed, and his mechanics, not he, were in charge of obtaining the videos. The order would come from the operations computer identifying the time and date of the video required. He did not see a video of bus 334 on 23 August 2013. -- 13 of 34 -- 14 [64] Conclusion: It is apparent from the evidence summarised above that, although a video recording was probably made of the interior of bus 334 at the time of the incident, none of the witnesses saw that video recording and the recording, if it existed, was not available for use in these proceedings. No suggestion was made that anyone deliberately hid, tampered with or destroyed the video. It simply is not in evidence and no inference can be drawn from that fact. Actions taken after the incident on 23 August 2013 [65] The Appellant's account: Some time after 9.00 am, the Appellant called Mr Browne to check whether the bus was cleared as serviceable for that day. Mr Browne replied that if the bus was allocated to the Appellant on the computer then it was serviceable for the day's work. The Appellant advised him that he had defected the seat the previous night and that seat had not been fixed. Apparently Mr Browne did not reply. The Appellant did not inform Mr Browne at that stage that he had injured his back. He explained that: "we injure ourselves every so often and we don't go running to the boss and say, hey, look, I've injured myself because normally we can repair, and I gave myself time to repair, and I thought maybe I could repair." (T1: 36, see also 50) At that stage, nobody offered the Appellant a replacement bus. [66] The Appellant continued on his route and had his lunch break at 11.55 am. At that stage he was at Harbour Town and was in "horrific pain" and was convinced that, after the time that had elapsed, his condition was not going to improve. At 12.30 pm, the Appellant reported the incident when he called base for a replacement driver. He spoke to a man he knew as Mal4 and said that he had a seat "bottom out" on him at Southport at 8.35 am. He needed a replacement driver as he was in too much pain to carry on. Apparently Mal said that he would pass this on to Mr Browne, who contacted the Appellant by phone. The Appellant said that he advised Mr Browne that he had injured his back and needed a replacement driver. He explained what had happened. Mr Browne asked why the Appellant had not told him there was something wrong with the seat before he left the depot at the start of the shift when the bus could have been changed. The Appellant reminded him that they had spoken after 9.00 a.m. that day and that Mr Browne had told him that the bus was fully serviceable there was nothing wrong with it. According to the Appellant, Mr Browne got quite upset with him and asked if he required an ambulance. The Appellant said he did not, and Mr Browne said he would send a header driver5 to him. When the Appellant referred to the broken seat and asked whether Mr Browne wanted to hurt somebody else's back by driving the same bus, Mr Browne shouted that the Appellant should tell the header driver to take his bus and finish his run. [67] When the replacement driver (Mr Wildman) arrived, the Appellant showed him the seat. Mr Wildman said that he would not take that bus. Rather, he drove the Appellant back to the base in the bus that Mr Wildman was driving, and someone else completed the Appellant's shift. 4 Malcolm Fraser. 5 A header driver is a driver who does not have specific shifts but is on call to attend to incidents around the coast. -- 14 of 34 -- 15 [68] On his return to the base, the Appellant reported to Mal at the operations window who asked him to come inside. The Appellant met John Luton who, the Appellant understood, had been sent to the Ernest depot to replace the absent operations manager. According to the Appellant, Mr Luton was very supportive and very sympathetic to what had happened to him. The Appellant told him everything that had occurred and Mr Luton called the WorkCover manager. At that stage, the Appellant handed in his daily takings and the Record of Daily Inspection sheet. [69] Mr Luton gave the Appellant a WorkCover pack and advised him to go directly to his doctor. The Appellant then attended on Dr Ralph Vida at Mermaid Junction Medical Centre and completed his Application for Compensation that day (Exhibit 7). [70] The Application for Compensation included the following information: (a) the injury was to lower spine, left and right SIJ (sacroiliac joints) (b) the injury occurred in the morning of 23 August 2013; (c) the injury happened over a period of time, in that he first experienced symptoms on 22 August 2013; (d) the injury happened due to a "broken driver's seat plus seat bottoming out when hitting hole in road works Southport;" (e) the Appellant advised his employer about the injury on 23 August 2013 when he reported to Colin Brown (operations); and (f) the Appellant previously had spinal surgery. [71] Dr Vida provided a workers' compensation medical certificate stating that the Appellant was suffering "lumbar sprain" and was not capable for any type of work from 23 to 26 August 2013. The Appellant did not return to work. Dr Vida provided further workers' compensation medical certificates. The Appellant continued to receive medication, and was subject to scans and various forms of treatment including cortisone injections. The treatment he received and the assessments of his condition from time to time by treating doctors are discussed later in these reasons (see Medical evidence). [72] Mr Fraser's account: Mr Fraser recalled having another conversation with the Appellant a couple of hours after their earlier discussion, when the Appellant called him on the operations phone and told him that he hurt his back and required a replacement driver. Mr Fraser then spoke to Mr Browne about getting the header shift to the Appellant at Harbour Town, then passed the phone to Mr Browne and proceeded to organise a replacement shift. [73] Mr Browne's account: Mr Browne denied having a conversation with the Appellant at about 9.00am, after the Appellant had left the depot. [74] Rather, Mr Browne said that he next spoke to the Appellant during the Appellant's lunchbreak, at 12.35 pm, after Mr Fraser advised him that the Appellant required a relief driver. Mr Browne called the Appellant who told him that his back was sore -- 15 of 34 -- 16 and that he could not drive any more. He had tingly legs and needed a replacement driver. Mr Browne said he would arrange a driver, and asked whether the Appellant required medical assistance.6 The Appellant said no, he was okay. Mr Browne then hung up and arranged to get a bus to the Appellant and bring him back to base. Mr Browne then called the Appellant and told him that he was sending his header driver to pick him up and bring him back to base. The Appellant said that was fine. The header driver (Mr Wildman) arrived at Harbour Town, the Appellant said his back was sore, and the header driver brought the Appellant back to the base in the replacement bus. [75] Mr Browne denied that he was angry with the Appellant at that time, but confirmed that he asked why the Appellant did not tell him about the seat being a problem earlier as they could have defected the bus and given him another bus straight away. But the Appellant had said that he would take the bus out and defect it when he returned at the end of the shift. Mr Browne also said that he did not offer to send a header driver with a replacement bus so that the Appellant could finish his shift in that replacement bus. A replacement driver was sent for the Appellant, not a replacement bus for the Appellant to drive. So Mr Browne sent two buses, one with a driver to complete the Appellant's shift (shift 4000) and the other for the Appellant's return to the depot (shift 3000). (Exhibit 15) [76] Mr Browne subsequently went to Harbour Town with Mr Wildman, to collect bus 334 and bring it back to the depot. Mr Browne found that the driver's seat was "in a very bouncy position" which he did not find comfortable to drive. He locked the seat to his personal setting and drove the bus back to the base. At 87 kilograms, Mr Browne is heavier than the Appellant. He could find no problem with the seat on that journey of about 10 kilometres over different types of road surfaces. In cross-examination, he stated "I could find absolutely nothing wrong with that seat when I was driving it." (T2: 76) [77] Mr Browne described the setting which he used when driving the bus as having "a little bit of dampener in the seat" so that there was "a little bit of movement." More specifically, he stated that could push a lever that would make the seat more solid so it would not respond to every bump and move up and down rapidly. It would be "more gentle movement, not rapid, physical up-and-down motion." That was distinguished from full movement up and down "because you can jar your back, I believe." In cross-examination he explained that his preferred setting could be made between the "solid hard" setting and "full flotation" so that there is "just gentle suspension, not quite as firm." He achieved this by using a ratchet lock which can adjust down. [78] On his return to the depot, Mr Browne advised Ned, the workshop mechanic, that the bus had been brought back due to the driver complaining that the seat was faulty. By that stage, the Appellant was seeing the operations manager, John Luton, at the depot. [79] Mr Wildman's account: On 23 August 2013, Mr Browne called Mr Wildman on the radio and told him to go to Harbour Town to take a bus to the Appellant because the 6 Mr Browne gave evidence that every driver who says they have an injury on the road is asked whether they request medical assistance. If they say they do, his next call would be to an ambulance with the relevant information. He has a duty of care to the driver but the drivers are adults and they know whether they are injured enough to require medical assistance. -- 16 of 34 -- 17 Appellant had hurt his back. He found the Appellant parked in the lay-up area and asked the Appellant whether he would like to drive the bus or if he wanted Mr Wildman to do so. The Appellant asked Mr Wildman to drive him to the depot, which he did. The Appellant told Mr Wildman that he had "stuffed his back" on the seat. They left the Appellant's bus locked. Mr Wildman did not go into that bus. He did not recall the Appellant saying the seat was broken or showing him a broken seat. [80] Mr Wildman rejected the suggestion that Mr Browne gave instructions that he should take the Appellant's bus and continue the Appellant's shift and finalise that round in his stead. Mr Wildman said that was not his role. Rather, there was another header that day who was told to go and finish the Appellant's run. [81] Although Mr Wildman later took Mr Brown back to pick up the other bus, he did not have an opportunity to inspect the seat of the bus and Mr Browne drove that bus back to the depot. [82] The Appellant said that he was not present when Mr Browne and Mr Wildman arrived to bring back his bus, and so could not comment upon their examination of the seat. Medical evidence [83] A key issue in this appeal is whether the Appellant suffered a work-related "injury" on 23 August 2013. To resolve that issue, it is necessary to understand the Appellant's medical history in relation to his back and to assess the expert medical opinion evidence. [84] Medical history: The Appellant was born in 1951. He joined the Royal Australian Air Force in 1969 and served for 12 years as a supply clerk at various locations. The Appellant said that he received a pension (at 40 per cent of the general rate) in respect of one condition accepted by the Defence Force in 2013 as attributable to defence service, lumbar spondylosis. [85] The Appellant was 62 at the time of the incident. He had experienced a series of issues with his back and knees, and had received treatment for specific injuries and conditions between 1994 and 2011. [86] The Appellant had a number of steroid cortisone injections into his back before surgery in 1994 when he had an L4/L5 fusion, a decompression laminectomy at L5, and an L5/S1 spinal fusion. Following that surgery, the Appellant did not work for approximately three years and had intermittent back pain until 2002. In late 1996, he started working for Blue Ribbon Coaches in Newcastle, gradually increasing from one a half hours each week to a 20 hour each week workload. [87] In 2002, he had his left sacroiliac joint fused. From then until 2010, he was pain-free in his back. [88] In May 2005 he had a knee injury after a fall in a bus which he was cleaning. In February 2006, he had a total left knee replacement. He has not experienced any problems with that knee since the operation. -- 17 of 34 -- 18 [89] Just before Christmas 2010, the Appellant aggravated and suffered chronic back pain while mowing on a slippery grass surface. Dr Neal Cleaver gave him epidural steroid injections in February 2011. [90] On 30 August 2011, Dr Cleaver operated on the Appellant's L2/L3 disc and the L3/L4 disc. The Appellant was cleared to return to work towards the end of 2011. He did so and attended on Dr Cleaver at least twice each year. [91] An X-ray of the lumbosacral spine on 27 August 2012, 12 months after the operation, found, among other things: (a) multilevel degenerative change with intervertebral disc space loss; (b) osteoporosis was evident; (c) the overall alignment of the lumbosacral spine was largely preserved; and (d) degenerative change at both sacroiliac joints. (Exhibit 16 B) [92] The Appellant gave evidence that in the period after recovering from his surgery on 30 August 2011 until the incident on 23 August 2013 he was generally free of pain and free of symptoms in his back. He said that after he returned to work he experienced "very little pain." He was able to work shifts of 10 to 12 hours daily for five days a week. "Sometimes I suffered a small amount of pain, but my back condition was great." He later stated that before the incident in August 2013 he was "pain-free" and had no pain or discomfort in either the left or the right sacroiliac joint. [93] However, the Appellant said that he saw Dr Cleaver on 21 December 2012 because he had "some pain, which was unexplained" which he described as "lower back pain." Kimberly Crossley, a project manager at Qscan Radiology, confirmed that, an X-ray was taken on 21 December 2012 and the clinical details recorded for the X-ray are "61 yr old with chronic back pain." The following findings were recorded in relation to the X-ray: "There has been a total disc replacement at L2/3. There has been left lateral fusion at L3/4 with a plate and vertebral body screws at each level. An intervertebral disc spacer is present at this level. There is very minor anterolisthesis of L5 in relation to L4. There have been previous L4 and L5 laminectomies and bony fusion is evident posterolaterally from L3 to S1. There has been good restoration of intervertebral disc height at the levels of disc replacement and lateral fusion. There is no evidence of bony encroachment on the neural foramina. There is moderate degenerative disc change at L1/2 and prominent marginal osteophytes are evident particularly anteriorly and laterally in the upper lumbar spine." (Exhibit 16B) [94] When asked about the X-ray and the reason for it, the Appellant described the doctor's annotation of "chronic back pain" as wrong. The Appellant said that the X-ray showed that everything was fine. His work was not interrupted and he returned to work on 22 December 2012. According to the Appellant, that was the symptom leading up to -- 18 of 34 -- 19 his mini stroke which he had two days later.7 After the mini stroke, "I had no pain at all. Then I went back to work." [95] The Appellant also explained that Dr Cleaver left a referral for a facet joint injection (Exhibit 11) so that, in Dr Cleaver's absence (overseas for seven weeks), the Appellant could phone the office and the injection would be administered if needed. According to the Appellant, the injection was never administered. The document was left on his file only. Evidence was given by Ms Crossley that the appointment for 7 January 2013 was cancelled. Although the Appellant acknowledged that the record in relation to that proposed injection (Exhibit 11) referred to "Chronic Back Pain," he insisted that he was not "suffering chronic back pain." Although his evidence in chief was that he had no specific back problems on 21 December 2012, it is clear from his evidence when cross examined that (as noted above) he saw Dr Cleaver in relation to some lower back pain on that date. [96] The Appellant also agreed, in cross-examination, that prior to 21 May 2013 he was experiencing back pain for which he obtained reasonable relief when taking tramadol. [97] When cross-examined about his evidence that he was pain-free in the lower back from the time of the surgery in August 2011, the Appellant said "Well, you have intermittent days. You have good days, bad days. But it didn't stop me from working, sir. Didn't stop me from working. … I stand by what I said, sir, yep. … Sir, what I mean by pain-free is I can still do a … 10 hour day, even though I have … small back pain, fine. … majority of the time I have been pain free." (T1: 83) The Appellant continued: "Since the - since the surgery I have been pain-free. This surgery has been very, very successful in allowing me to go back to work and do my full shift. As there are no lighter shifts available I had to go back to my full roster of 10 hours a day on a nine day roster. Yes, it - it is just human that we have a little pain here and there, and I did mention it to the doctor at that time. But it at no time stopped me from working. … After - after having surgery, you know, my back has had little twinkles here and there. … But the majority of my life has been pain-free since the surgery." (T1: 83-84) Later he stated: "Being able to complete a 10 hour day, 10, 12 hour day in the seat, and that is my terminology for pain free. If I can do that five days a week, regardless of small issues with [my] back, I'm – that's what I term as pain free." (T2: 8) [98] In re-examination, the Appellant said that by "pain-free" he meant that "the doctor has done his job, and allowed me to regain my employment status back." (T2: 38) 7 According to the Appellant, he was driving home from work on 23 December 2012 when his left arm and left leg became quite severely disabled, and he was conveyed to Robina Hospital with a suspected mini- stroke. -- 19 of 34 -- 20 [99] The Appellant agreed that, in the period after he recovered from surgery in 2011 until the incident in August 2013 he suffered cyclical low back pain "on occasions." When asked whether that was in stark contrast to his previous evidence about no pain, he replied "I guess so. Yes." [100] Following the incident on 23 August 2013: (a) the Appellant had a spinal block at L2/L3 on 14 January 2014 and a bilateral sacroiliac joint block on 18 March 2014; and (b) on 17 April 2014, Dr Cleaver commenced surgery on the right sacroiliac joint but that surgery had to cease early because the Appellant went into cardiac arrest. Consequently Dr Cleaver was only able to insert two pins (rather than three pins as intended) in the right sacroiliac joint. He did not operate on the left sacroiliac joint as scheduled on 22 April 2014. [101] Expert medical opinion evidence: Although it is clear that the Commission must decide whether the Appellant's alleged injury arose out of, or in the course of, his employment and whether his employment was a significant contributing factor, the Commission can be assisted by expert opinion of a medical practitioner who has an accurate understanding of the injury and the circumstances in which it occurred.8 Two doctors gave medical opinion evidence: (a) Dr Ralph Vida, a general practitioner who has been in practice for about 30 years and has treated the Appellant since 2011; and (b) Dr Neil Cleaver, an orthopaedic surgeon specialising in the spine who has been in practice since 1996. [102] Dr Vida: Dr Vida gave evidence in chief that: (a) he first met the Appellant in 2011, relatively recently after the Appellant had surgery; and (b) although the Appellant had consulted Dr Vida on lots of occasions in relation to general medical problems, he had not mentioned any back complaint before 23 August 2013. In Dr Vida's opinion, the Appellant had "done remarkably well." [103] However, it is apparent from Dr Vida's consultation notes (Exhibit 8) and his oral evidence when cross-examined that: (a) he first saw the Appellant on 24 February 2011; (b) on 11 December 2012, the Appellant saw Dr Vida for a treating doctor's report in relation to an application for an increase in disability pension,9 apparently on the basis of a list of conditions including "back problems" (but Dr Vida was not able to say whether any of the back problems were attributable to defence 8 See e.g. Q-COMP v Parsons (2007) 185 QGIG 1, 3 (Hall P); R v Turner [1975] QB 834, 840 (Lawton LJ); Pollock v Wellington (1996) 15 WAR 1, 3 (Anderson J). 9 In his oral evidence the Appellant confirmed that he was seeking a full disability pension. -- 20 of 34 -- 21 service, or whether the Department of Veterans' Affairs ("DVA") had accepted that condition); (c) on 21 May 2013, Dr Vida referred to an expected flare of lower back problems (apparently related to an incident on 28 December 2012 when the Appellant experienced pain in his left shoulder when swinging his three-year-old grandson around); but he could not say whether the Appellant actually had back pain on the day. [104] When the Appellant consulted him on 23 August 2013, he complained of lower back pain in the lumbar region with some associated stiffness that had been present following an incident at work. The Appellant said he had jarred his back following the use of a bus that had a malfunctioning seat. [105] Dr Vida noticed that, when coming up the hallway to enter the consulting rooms, the Appellant was "very slow and measured with his gait" and looked to be bent forward at the waist. He was in "quite some pain" and sat with "quite a degree of difficulty" in the chair. Dr Vida's consultation notes record, however, that he "sits with complete comfort." [106] Dr Vida said that he did not examine the Appellant in detail but conducted a limited physical examination to see if there was any tenderness in the area of his sacroiliac joints and lumbar spine. Dr Vida agreed that there was a fair degree of subjectivity to such an examination. Dr Vida said he did not proceed through a range of movement or tenderness at the consultation because he did not feel it was going to add much clinical value. [107] Although he noted that the Appellant was tender at both sacroiliac joints, Dr Vida did not make a specific clinical finding. Rather he stated that the Appellant indicated that the area of soreness was the lower spine, and that took in most of the lumbar region. The Appellant had AROM flexion to mid thigh but could not bend backwards at all. Dr Vida did not consider it was necessary to be specific with the Appellant's background history of operations. He could not comment on whether the sacroiliac joints were specifically involved on the occasion of that presentation. The Appellant had "a lot of scar tissue … And other issues that affect his pain referral." [108] Dr Vida issued a workers' compensation medical certificate which stated that the Appellant was not capable for any type of work between 23 and 26 August 2013 (inclusive). The recorded diagnosis was "lumbar sprain," and the worker's stated cause of injury was recorded as "compression jolt from malfunctioning driver's seat at work" (Exhibit 9). [109] When the Appellant attended Dr Vida on 26 August 2013, Dr Vida was "quite surprised" that the Appellant was very stiff and unable to lift his left foot to apply the brake in the car, and was experiencing significant buttock pain. Dr Vida had considered that, given some modest time with which to settle most of his soreness, the Appellant should have improved. In fact, "he was worse, barely moving at all." The Appellant "didn't seem to be an average case at all of back sprain." Dr Vida agreed that the jarring of the Appellant's back from a malfunctioning seat was a fairly low- scale physical trauma, and continued: -- 21 of 34 -- 22 "That was the reason for my surprise. I always have regards for the forces involved with accidental trauma especially road traffic accidents, and I felt the suspension even if on the driver's seat was inadequate the suspension under the chassis of the bus certainly would have been very compliant for passenger comfort. So I was surprised that he could have sustained anything that led him to anything more than just a short-term problem." (T1: 59) [110] Dr Vida reassured the Appellant and encouraged him to "mobilise". Dr Vida prescribed a stronger than normal opiate-based drug for pain relief, and issued a medical certificate which declared him not capable for any type of work from 27 August 2013 until 2 September 2013. Again the diagnosis was "lumbar sprain" (Exhibit 9). [111] On 2 September 2013, the Appellant again consulted Dr Vida who stated that there "was really no improvement whatsoever." Dr Vida felt that it was important not to waste too much more time, and he sent the Appellant to his spinal surgeon (Dr Neil Cleaver), who Dr Vida felt "actually knew his back well." Dr Vida increased the dosage of medication slightly. He issued a medical certificate stating that the Appellant was not capable for any type of work from 2 until 8 September 2013. Again the diagnosis was "lumbar sprain" (Exhibit 9). [112] On 2 September 2013, Dr Vida wrote a letter of referral to Dr Cleaver in which he referred to the Appellant having presented on 23 August 2013 as having jarred his back at work from using a bus with malfunctioning seat squab. The Appellant had adjusted the seat setting to soft and "found he bottomed its outgoing thru roadworks and the sudden axial load ppt his LBP." Dr Vida stated that, despite a week of rest and opiates, the Appellant continued to have significant lower back pain, especially over the sacroiliac joint and associated stiffness with referred pain over buttock to mid thigh posteriorly (Exhibit 12). [113] The Appellant consulted Dr Vida next on 9 September 2013. The consultation notes record that the Appellant maintained that he was "unimproved." The pain varied. Occasionally he slept through the day and at times could not sleep at night. He was awaiting assessment by Dr Cleaver on 25 September 2013. The notes continue: "hobbles in with exaggerated antalgic gait and facial expressions but sits and converses freely when I remarked that he is sitting freely and could do so at work (office duties) John replied that he is holding his weight on the armrests there is an element of abnormal illness behaviour here I believe his litany of complaints to generate escalation of his DVA status (has achieved Gold Card by the way with recent addition of spondylitis to his accepted disabilities) and background GAD10 is my reason for suggesting this" (Exhibit 8). [114] Dr Vida: 10 Generalised anxiety disorder. -- 22 of 34 -- 23 (a) agreed that the underlying rationale for the DVA accepting spondylosis as a condition under the relevant legislation is that the condition was related to the Appellant's defence employment; (b) noted that spondylosis is a progressive disease that has various manifestations over considerable time; (c) agreed that the Appellant had a badly degenerative spine. [115] Dr Vida also expanded on his reference to "abnormal illness behaviour." His impression was that it was secondary to anxiety by the Appellant in relation to his symptoms more than the Appellant trying to "put one over" Dr Vida. Previously when the Appellant had a flare of back pain, he was keen to get back to work and Dr Vida felt that had not been the case with this back injury. In the past, the Appellant had been "quite honest in relation to his presentations." Dr Vida felt that the Appellant's "extraordinary presentations" were as much to do with his alarm than anything on that particular day. [116] Although Dr Vida was not able to tell how much of the Appellant's weight he was bearing on his elbows on the armrests of the patient chair, Dr Vida felt that the Appellant's response to his remark was "probably quite genuine." [117] Dr Vida subsequently issued a medical certificate on 9 September 2013 which declared that the Appellant was not capable of any type of work between 9 and 12 September 2013, and listed the diagnosis as "lumbar sprain". [118] When the Appellant consulted Dr Vida on 13 September 2013, Dr Vida recorded: "gait improving as can lift foot more easily but still woefully slow tolerating sitting for 20 min (drove here) miserable cooperation unknown has another two weeks wait for Neil [Cleaver] encouraged to try some work next week" (Exhibit 8). [119] Dr Vida issued a medical certificate on 13 September 2013 that listed the diagnosis as "lumbar sprain", declared the Appellant not capable of any work between 13 and 15 September 2013, and stated that the Appellant would have capacity for suitable duties from 16 to 20 September 2013, during which period he should vary his posture every half hour. Lifting, bending/twisting/squatting, pushing/pulling, and operating machinery/heavy vehicle were not approved. Occasional driving of a car was approved. Dr Vida required a suitable duties program to be provided to him for approval (Exhibit 9). [120] Dr Cleaver: In a letter to the Appellant's solicitors dated 12 February 2014, and in response to questions asked by those solicitors, Dr Cleaver wrote: "A. Mr. Coomber reported to me that on 23rd August he had a jarring incident at work as a result of malfunctioning seat on the bus he was driving. From the history that I took from John it appeared that this significantly aggravated his lumbar spine. Prior to this incident he was doing exceptionally well with very -- 23 of 34 -- 24 little in the way of pain and very little in the way of dependence on strong narcotics. When I reviewed him on 25th September 2013, he was quite disabled with severe pain on the left hand side of his lower spine. I examined him at that time and found tenderness over the region of his left cluneal nerve, so I took the liberty of injecting that. I also elected to investigate him and treat him by injecting his sacroiliac joints. His response to the injections was very good in the sense that on the right hand side of his back his pain completely disappeared. On the left hand side the pain completely disappeared following the injection, but returned 5 days later. The bone scan that Mr. Coomber had that I organized showed increased activity in the sacroiliac joint on the left hand side. … C. The presentation that Mr. Coomber displayed is consistent with a jarring activity as a result of a faulty bus seat." (Exhibit 12) [121] In his oral evidence, Dr Cleaver confirmed key aspects of what he had written to the Appellant's solicitors on 12 February 2014. Dr Cleaver confirmed that he relied on the Appellant's account of the incident to form the opinion that it appeared that the Appellant significantly aggravated his lumbar spine, and that the only objective clinical sign that he found when examining the Appellant was a tenderness over the region of the cluneal nerve. [122] Dr Cleaver said that investigations were performed that led to a diagnosis that the source of the pain was the sacroiliac joint, but agreed that: (a) none of the investigations revealed the presence of any discrete trauma or injury to his sacroiliac joints; (b) when he operated on the Appellant on 17 April 2014 he found "extreme osteoporosis" (a softening of the bone, which is a constitutionally degenerative condition) in the area of the right sacroiliac joint; and (c) as a result of his back condition, the Appellant could be prone to experience some measure of back pain from any minor event (Exhibit 12). [123] That evidence has to be considered by reference to the history of the Appellant's back condition, and the surgery and other treatments administered to the Appellant, most of which were described in a series of reports by Dr Cleaver and in his oral evidence. [124] In a report dated 17 January 2011, Dr Cleaver noted that he had seen the Appellant that day in relation to his "spinal condition." Dr Cleaver reported the Appellant's story that: (a) he had an L4-5 fusion and decompressive laminectomy in 1994 which gave the Appellant 16 years of "tremendous relief of pain;" (b) he had a resurgence of his symptoms and a few years later, following successful injections, had his left sacroiliac joint fused, following which his pain was "well controlled" for many years; -- 24 of 34 -- 25 (c) just before Christmas 2010, he was gardening and had been incapacitated since then with lumbar pain and, more recently, symptoms in his left leg (Exhibit 12). [125] Dr Cleaver reviewed an MRI scan which revealed: (a) what looks like a "solid fusion" at L4-5, without any instrumentation, and without any attempt to reconstruct height or lordosis; (b) L5-S1 is "extremely degenerate" and an attempt at a decompression posterior to that; (c) the disks higher up are all degenerate; and (d) there is "a cascade of degeneration from T12-L1 down to L3-4, with instability and lateral recess neural compression at each level" (Exhibit 12). Dr Cleaver agreed that there was fairly widespread degeneration of the spine which was constitutional and genetic. He was convinced that the Appellant's symptoms at that time were coming from his spine, and Dr Cleaver described the types of investigations he intended to undertake. [126] On 11 February 2011, Dr Cleaver saw the Appellant again and, having reviewed X-rays and a CT scan, decided to try injections of epidural steroids at two levels to help the Appellant with his pain. An injection was subsequently performed at L2/L3 and apparently was successful, both as a diagnostic tool for Dr Cleaver and as a therapeutic measure for the Appellant. However, it was not a permanent solution. On 4 March 2011, Dr Cleaver noted that, although the Appellant was on reduced medication and apparently had few remaining symptoms, the effect of the injection "will actually wear off at some point in the future." Dr Cleaver advised that, although there were no real restrictions on what the Appellant could or could not do, common sense should prevail and he should "take it easy." When he feels that the injections are wearing off, the Appellant should see Dr Cleaver again (Exhibit 12). [127] On 28 March 2011, Dr Cleaver reported that the Appellant was doing something a few days previously and had aggravated his symptoms. The aggravation lasted about two days. The Appellant was "feeling all right at the moment" and the injection of epidural steroids was still in effect (Exhibit 12). [128] Having diagnosed the Appellant as having "adjacent segments degeneration causing discogenic back pain and mechanical instability," Dr Cleaver performed surgery on 30 August 2011 involving an L2-3 total disk replacement and an L3-4 extreme lateral interbody fusion. [129] On 3 October 2011, Dr Cleaver reported to Dr Vida that, four weeks after the reconstruction at the L2-3 and L3-4, the Appellant felt about 50-60 per cent improved from his pre-operation status. Dr Cleaver described the Appellant as "much improved" and suggested that he would continue to improve. He noted that the results of reconstructive spine surgery when the patient has had previous reconstructions "always are a little bit less than working on a de novo spine" (Exhibit 12). -- 25 of 34 -- 26 [130] On 31 October 2011, Dr Cleaver reported to Dr Vida that the Appellant was "doing extremely well" and the only medication he was taking on a regular basis was Panadol. The Appellant reported his back pain was at least 80 per cent improved following his surgery and was "very keen" to get back to work. Dr Cleaver fully was "extremely happy" with the Appellant's improvement and supported him in the venture. He expressed some caution about the Appellant returning to work 12 hours a day for four days a week so soon after reconstructive surgery but noted that the Appellant said there was "no halfway house" for him when he returned to work. Although Dr Cleaver could not see any real restriction in terms of the Appellant's anatomy in this regard, he would caution the Appellant that if he feels that he has gone back to work too soon he "should not hesitate but to back off" (Exhibit 12). [131] Dr Cleaver saw the Appellant again on 15 February 2012, and recorded the Appellant saying he was about 90 per cent improved as a result of the procedure. According to Dr Cleaver, the Appellant: "still has days where he feels like that he gets in and out of a chair a bit like an old man. This is related to his loss of lumbar lordosis11 around the bottom section of his spine, which was operated on many years ago. Unfortunately, this means he has to rely on his own musculature to keep his head centred over his pelvis and is largely responsible for that component of his symptoms." (Exhibit 12) [132] As noted earlier, on 2 September 2013, Dr Vida referred the Appellant to Dr Cleaver for an opinion and management in relation to the condition of his jarred back following the incident on 23 August 2013. Dr Vida reported that, despite a week of rest and opiates, the Appellant continued to have significant lower back pain (especially over the sacroiliac joint) and some stiffness with referred pain over his buttock to mid thigh posteriorly (Exhibit 12). [133] Dr Cleaver saw the Appellant on 25 September 2013 and noted that the Appellant reported the incident and that he "bottomed out very heavily giving himself an axial compression injury to his lumbar spine." Dr Cleaver wrote that the Appellant "certainly aggravated something." Prior to that, the Appellant was doing "exceptionally well" with very little pain or dependence on strong narcotics. Now he was "quite disabled" and had pain to the left-hand side of his lower spine. Having examined the Appellant, Dr Cleaver found "absolute exquisite tenderness over his left cluneal nerve"12 and injected the cluneal nerve in his clinic and the sacroiliac joints with some hydrocortisone and local anaesthetic in hospital. Dr Cleaver thought it would be judicious to have a bone scan performed to ascertain whether the Appellant had not aggravated a facet joint or his sacroiliac joint. He noted that the CT scan that Dr Vida performed recently showed nothing significant had happened to the Appellant's reconstruction. However, "this injury has inflamed some entity causing his current set of symptoms" (Exhibit 12). [134] On 2 December 2013, Dr Cleaver reported that, following the hydrocortisone injection: (a) the pain on the Appellant's right side had disappeared; 11 The natural backward curvature of the spine in the lumbar region. 12 Located at the very bottom of the spine over the pelvic or iliac crest. -- 26 of 34 -- 27 (b) the pain on his left side had practically disappeared from about five days and then returned, and the Appellant remained "very symptomatic" on the left side. Dr Cleaver described the previous surgery to fuse the left sacroiliac joint as having failed, on the basis that it is active on the bone scan and because of the Appellant's response to the injection. He had offered the Appellant a number of possibilities to treat this (Exhibit 12). [135] Dr Cleaver expressed the opinion that, but for the incident on 23 August 2013, the prognosis in relation to the Appellant's left and right sacroiliac joints would have been "very good." [136] Medical evidence and Appellant's application for a disability pension: Concurrently with receiving treatment in relation to his back, the Appellant sought (ultimately successfully) a disability pension from the DVA. It is appropriate to note briefly the evidence in relation to the Appellant's actions, and the written support of Dr Vida and Dr Cleaver, to distinguish between that process and the basis for the application for compensation with which is the subject of this appeal. [137] According to the Appellant, the DVA rejected all of the conditions (apart from lumbar spondylosis) listed in December 2012 in his representation to the DVA for a disability pension. However his pension was increased to 100 per cent in early 2014 (backdated to 3 October 2013) due to a range of other factors being included in impact on his lifestyle. On 11 December 2012, the Appellant did not know that his pension was going to be increased to 100 per cent. [138] In a letter dated 13 January 2014 and addressed To Whom It May Concern, Dr Cleaver wrote as the Appellant's treating spine surgeon: "John has got severe, disabling chronic lower back pain secondary to degenerative disc disease, i.e., lumbar spondylosis. It is my professional opinion that considering the level of symptoms he has and the chronicity and severity, he is to be considered totally and permanently disabled with regards to his capacity for future employment and it is my professional opinion that with regards to his level of experience and education he will not work in any capacity in the future. Please do not hesitate to contact me if clarification is required." (Exhibit 12) [139] Dr Cleaver gave evidence that the letter was written at the request of the Appellant in order to assist the Appellant to be considered totally and permanently disabled so that he could collect some income. The letter mentions the Appellant's condition (lumbar spondylosis, his constitutionally degenerative back condition) as a result which he has no capacity to engage in employment. [140] Dr Vida signed a letter dated 28 January 2014 addressed To Whom It May Concern in which he stated: "I have been treating general practitioner for the above named gentlemen over the last three years -- 27 of 34 -- 28 Mr Coomber has chronic spinal disease namely lumbar spondylosis This condition has been fluctuant at times in symptoms and signs but progressive and now end stage He is unable to work in any capacity, seated or otherwise, and his prognosis for recovery to gainful employment is poor." (Exhibit 10) He agreed that the letter was written for possibly more than one purpose, including in the context of a Work Cover claim and in respect of the Appellant seeking a totally and permanently incapacitated pension from the DVA. Dr Vida clearly stated that he was not trying to convey in the letter that the incident on 23 August 2013 was the reason why the Appellant was unable to work in any capacity. He added, "I wouldn't have made that connection" and that was not his thinking at the time he wrote the letter. [141] In his report dated 17 January 2011, Dr Cleaver described the Appellant as having "a very strong work ethic" in regard to his work as a bus driver for Surfside Buses (Exhibit 12). As noted earlier, on 31 October 2011, Dr Cleaver reported to Dr Vida that the Appellant was "doing extremely well," the Appellant reported his back pain was at least 80 per cent improved following his surgery and was "very keen" to get back to work. However, Dr Vida formed the view in September 2013 that the Appellant was not as keen to return to work. [142] The Appellant rejected any suggestion that: (a) his attempt on 11 December 2012 to expand the list of conditions from which he was suffering in order to obtain a full disability pension from the DVA was because he wanted to retire rather than continue working; indeed he contended that if the DVA accepted those conditions he would still be allowed to work full-time ("I love my job and I want to keep working as a bus driver"); (b) the incident on 23 August 2013 was an attempt to seek another avenue compensation in lieu of his abandoning, on 21 August 2013, obstructive sleep apnoea as an additional condition for the purpose of his DVA disability pension. He asserted that the incident at work was "completely and totally separate" because it was a "break" to his sacroiliac joints and "just nothing else but that." Consideration and conclusions [143] It is apparent from the outline of issues earlier in these reasons and the summary of evidence that it is necessary to decide: (a) the circumstances in which the alleged injury occurred (and hence whether his injury arose out of, or in the course of, his employment); (b) whether the Appellant suffered an injury; and -- 28 of 34 -- 29 (c) if so, whether the Appellant's employment was a significant contributing factor to the injury. [144] The circumstances in which the alleged injury occurred: Having regard to the written and oral evidence, and the demeanour of the witnesses, I find that: (a) on 22 August 2013, the Appellant drove bus 334 in the course of his employment and experienced some soreness in his "pretty sensitive" back when the bus hit a bump; (b) the Appellant considered that the driver's seat in bus 334 was defective; (c) on his return to the depot that afternoon, the Appellant defected the bus for the stated reason that it catapults upwards over bumps and jerks drivers' backs; (d) that evening, Mr Collins inspected and tested the driver's seat in bus 334 and found it fully functional with no defect to the seat shock absorber; (e) on the morning of 23 August 2013, the Appellant was allocated bus 334 to drive that day; (f) the condition of the driver's seat in that bus was unchanged from its condition on 22 August 2013; (g) having performed the usual pre-shift inspection and other activities in relation to the bus, the Appellant formed the opinion that the driver's seat was defective; (h) the Appellant recorded on the Record of Daily Inspection that the seat was defective; (i) having formed that opinion, the Appellant adjusted the seat to the soft setting; (j) the soft setting (although not inherently unsafe) was generally unsuitable for driving a bus in the conditions encountered on the route allocated to the Appellant for that day; (k) at approximately 8.35 a.m., the Appellant drove the bus along Scarborough Street across the intersection with Nerang Street; (l) the bus was travelling at approximately 20 km/h when its left wheel struck a pothole in Scarborough Street; (m) the padded level of the driver's seat dropped momentarily and at most the plate supporting the seat padding might have touched the rubber bump stop before moving upward; -- 29 of 34 -- 30 (n) the Appellant immediately experienced symptoms of strong pain in his lower back, and that pain continued for some time after the incident. [145] For the purposes of deciding this appeal, it is not necessary to make findings in relation to whether or when some other disputed events occurred (e.g. conversations between the Appellant and others at the depot) or the degree and duration of the pain suffered by the Appellant after the incident. [146] For present purposes it is sufficient to find that the incident occurred and that the Appellant felt significant pain in his lower back as a consequence of it. The central issue is whether he suffered an "injury" as a result of the incident. To answer that question it is necessary to look carefully at the medical evidence, in particular the diagnoses made by Dr Vida and Dr Cleaver in the weeks immediately after the incident. [147] Nature of the injury: The injury ultimately asserted in these proceedings is an aggravation of a pre-existing condition. The Appellant contends that: (a) immediately before the incident on 23 August 2013, he had no lower back symptoms; and (b) the lower back pain originated at the time of that incident and gradually worsened. [148] As to the first point: (a) the Appellant's own evidence was that he experienced lower back pain on occasions in the period since he recovered from his operation in August 2011; (b) the Appellant's definition of being pain-free was that, although he experienced some back pain including "twinkles", and had some bad days, he remained physically able to perform his work on a full-time basis; (c) there was other evidence that he had sought medical treatment in relation to lower back symptoms on two occasions (on 21 May and 21 December 2012); (d) by his own account, after the Appellant drove bus 334 over a bump on 22 August 2013, his back (which was very sensitive to these things) was a little bit sore with the bouncing up and down, as a result of what he considered to be a damaged driver's seat. [149] Accordingly I find that the Appellant experienced some lower back pain on occasions in the period after he recovered from his operation in August 2011 but that lower back pain, when it occurred, did not prevent him being able to perform his work on a full- time basis. [150] In order to determine whether the Appellant suffered an "injury" as a result of the incident on 23 August 2013, it is necessary to bear in mind the condition of the -- 30 of 34 -- 31 Appellant's lumbar region immediately before that incident. The evidence set out earlier shows that (working down the spine) in summary: (a) there was moderate degenerative disc change at L1/L2; (b) there had been a total disc replacement at the L2/L3; (c) there had been a lateral interbody fusion at L3/L4; (d) there had been a fusion of L4/L5; (e) there had been a decompression laminectomy of L5; (f) there had been a fusion of L5/S1; (g) there had been a fusion of the left sacroiliac joint; (h) there were signs of multilevel degenerative change with intervertebral disc space loss and degeneration at both sacroiliac joints (which degeneration was constitutional and genetic); (i) osteoporosis was evident (and, when incomplete surgery occurred in April 2014, Dr Cleaver found extreme osteoporosis in the area of the right sacroiliac joint). [151] Although there was a reasonable volume of medical evidence in relation to the condition of the Appellant's spine and the history of treatments in relation to it, there was less evidence about the precise natrue of the subject injury. The Appellant's Application for Compensation form (Exhibit 7) described his injury as "lower spine, left and right SIJ" (sacroiliac joint). There was evidence that the application was completed by the Appellant with the assistance of Dr Vida, relatively soon after the incident on 23 August 2013. [152] It is apparent from the written and oral medical evidence that: (a) On 23 August 2013, Dr Vida noted that the Appellant was tender at both sacroiliac joints, and the Appellant indicated that the area of soreness was the lower spine (which took in most of the lumbar region), but Dr Vida could not say whether the sacroiliac joints were specifically involved on the occasion of that presentation (apparently because scar tissue and other issues affect the Appellant's pain referral); (b) Dr Vida recorded a diagnosis of "lumbar sprain" on four workers' compensation medical certificate that he issued between 23 August 2013 and 13 September 2013 (before the Appellant had seen Dr Cleaver); (c) Dr Vida was surprised that the symptoms had not improved and, given the fairly low scale physical trauma, he had expected this to be a short term problem; -- 31 of 34 -- 32 (d) on 2 September 2013, Dr Vida reported that despite a week of rest and opiates, the Appellant continued to have significant lower back pain (especially near the sacroiliac joint); (e) Dr Vida separately, and some months after the incident on 23 August 2013, diagnosed the Appellant having lumbar spondylosis, but did not try to convey that the incident was the reason why the Appellant was unable to work in any capacity; (f) Dr Cleaver was familiar with the Appellant's back, having been consulted about his spinal condition in January 2011 and operated on the back in August 2011; (g) Dr Cleaver was aware that the Appellant had widespread degeneration of the spine (lumbar spondylosis) and considered that the Appellant was doing extremely well after his 2011 surgery; (h) when Dr Cleaver reviewed him on 25 September 2013, he found that the Appellant was quite disabled with severe pain on the left-hand side of his lower spine; (i) Dr Cleaver stated that the only objective clinical sign that he found when examining the Appellant on 25 September 2013 was an exquisite tenderness over the region of the left cluneal nerve, but expressed the view at that date that the Appellant "certainly aggravated something" and that the injury had "inflamed some entity causing his current set of symptoms;" (j) investigations performed led Dr Cleaver to diagnose that the source of the pain was the sacroiliac joint, but he agreed that none of the investigations revealed the presence of any discrete trauma or injury to the Appellant's sacroiliac joints; (k) Dr Cleaver expressed the opinion that, but for the incident on 23 August 2013, the prognosis in relation to the Appellant's left and right sacroiliac joints would have been very good; (l) there was osteoporosis, or a constitutionally degenerative softening of the bone, at the sacroiliac joint and Dr Cleaver agreed that, as a result of his back condition, the Appellant could be prone to experience some measure of back pain from any minor event; (m) on 2 December 2013, Dr Cleaver described the previous surgery to fuse the left sacroiliac joint as having failed, on the basis that it was active on the bone scan and because of the Appellant's response to a hydrocortisone injection; (n) in his letter dated 12 February 2014, Dr Cleaver stated that the Appellant's presentation was "consistent with" a jarring activity as a result of a faulty bus seat and, based on the history of the incident provided by the Appellant, it appeared that the incident "significantly aggravated his lumbar spine." -- 32 of 34 -- 33 [153] The overall effect of the evidence is that the Appellant suffered much more than lumbar sprain as a result of the incident on 23 August 2013. His condition did not improve in the way anticipated by Dr Vida, but deteriorated to the point where significant surgery was recommended and commenced in April 2014. [154] At the hearing, counsel for the Appellant submitted that the injury was an aggravation of the pre-existing spondylosis. [155] Although the onus to be discharged is on the balance of probabilities, the Commission, in dealing with the matter, must feel an actual persuasion before the alleged facts can be found to exist. The mere possibility of an appellant suffering an injury is not enough. There is a distinction between reasonable deduction from evidence and mere conjecture. Inference must be carefully distinguished from conjecture or speculation. There can be no inference unless there are objective facts from which to infer the other facts which it is sought to establish.13 [156] While there is room for intuitive reasoning when determining whether a worker has suffered an injury within the meaning of the Act, in the process of determining that question of fact, the Commission cannot substitute speculation for satisfaction on the balance of probabilities.14 [157] In a case where expert medical evidence is led, before any such expert medical evidence be of value, the facts upon which it is founded must be proved by admissible evidence.15 [158] On the basis of the medical evidence in relation to the nature of the Appellant's condition on and after 23 August 2013, and the Appellant's evidence about the condition of his back from time to time, I am persuaded that on 23 August 2013 the Appellant suffered an aggravation of both his pre-existing lumbar spondylosis and the degeneration to his left sacroiliac joint. That aggravation constituted an "injury" for the purpose of s 32(3) of the Act. [159] In reaching the relevant level of satisfaction to decide this appeal, I have not relied simply on the opinions of medical experts formed after the incident on 23 August 2013 that the Appellant's condition from that date onwards constituted a significant aggravation of his lumbar spine and the condition of his left sacroiliac joint. Those opinions were formed not only by reference to symptoms presented by the Appellant on and after that date, and other investigations. The opinions have additional weight because they drew on: (a) the examinations and observations of the Appellant made by Dr Vida and Dr Cleaver since early 2011 including, significantly for present purposes, the Appellant's progress since his surgery in August 2011; and (b) the history of their treatment of the Appellant in that period including, in the case of Dr Vida, treatment in relation to a range of medical matters unrelated to the Appellant's back. 13 See MacArthur v WorkCover Queensland (2001) 167 QGIG 100, 101 (Hall P) and cases cited. 14 Nilsson v Q-Comp (2008) 189 QGIG 523, 526 (Hall P). 15 Pollock v Wellington (1996) 15 WAR 1, 3 (Anderson J), R v Turner [1975] QB 834, 840 (Lawton J) quoted in Coombes v Q-Comp (2007) 185 QGIG 331, 334-335 (Edwards C). -- 33 of 34 -- 34 [160] Whether injury arose out of, or in course of, Appellant's employment, and employment was a significant contributing factor to the injury: The remaining issue is whether the Appellant's injury arose out of, or in the course of, his employment, and whether his employment was a significant contributing factor to the injury. [161] The evidence of Dr Vida and Dr Cleaver was to the effect that the Appellant had made a very good recovery from his surgery in 2011 and that there was no clinical reason for him not to return to work. The Appellant returned to work, doing full shifts until 23 August 2013. It is also clear from the evidence of Dr Vida and the Appellant that, once he had recovered from the surgery, the Appellant had experienced few symptoms of lower back pain before 22 August 2013. [162] In his oral evidence, Dr Cleaver expressed the opinion that: (a) based on the history he took from the Appellant, it appeared that the incident on 23 August 2013 "significantly aggravated his lumbar spine;" (b) but for the incident on 23 August 2013, the prognosis in relation to the Appellant's left and right sacroiliac joints would have been "very good." In his letter to the Appellant's solicitors dated 12 February 2014, Dr Cleaver wrote that the Appellant's presentation was "consistent with a jarring activity as a result of a faulty bus seat." [163] Earlier in these reasons for decision, I set out my findings in relation to the incident on 23 August 2013 (see [144]). Given those findings and the medical evidence, I am satisfied that the Appellant's injury arose in the course of the Appellant's employment as a bus driver. [164] In light of the medical evidence in relation to causation and the Appellant's account of the incident on 23 August 2013, and in the absence of any evidence to suggest that the injury was caused by anything other than the incident,16 I am satisfied that the Appellant's employment was a significant contributing factor to his injury. [165] Accordingly I make the following orders: (a) the appeal is allowed; (b) the decision of the Workers' Compensation Regulator is set aside and substituted with a decision that the claim for compensation is one for acceptance; (c) the Respondent is to pay the Appellant's costs of and incidental to the appeal to be agreed or, failing agreement, to be subject of a further application to the Commission. 16 See Fielder v WorkCover Queensland (2004) 175 QGIG 871, 872 (Hall P). -- 34 of 34 --