Clermont Coal Operations Pty Ltd v Workers' Compensation Regulator [2017] QIRC 35

QUEENSLAND INDUSTRIAL RELATIONS COMMISSION CITATION: Clermont Coal Operations Pty Ltd v Workers' Compensation Regulator [2017] QIRC 035 PARTIES: Clermont Coal Operations Pty Ltd (Appellant) v Workers' Compensation Regulator (First Respondent) and Paul Ebsworth (Second Respondent) CASE NO: WC/2016/160 PROCEEDING: Appeal against a decision of the Workers' Compensation Regulator DELIVERED ON: 27 April 2017 HEARING DATES: 12, 13, 14 December 2016 HEARD AT: Brisbane MEMBER: Industrial Commissioner Black ORDERS: 1. 1. The Appeal is allowed; 2. 2. The decision of the regulator dated 12 August 2016 is set aside; 3. 3. Costs are reserved. CATCHWORDS: WORKERS' COMPENSATION - APPEAL AGAINST DECISION – physical injury claim relating to an annular tear – claim associated with an earlier accepted claim for an aggravation to the lumbar spine - whether annular tear should be considered a separate injury; whether annular tear caused by an acute event or by degeneration. CASES: Workers' Compensation and Rehabilitation Act 2003, s 32(1), s 550. APPEARANCES: Mr T Forno, Solicitor, Minter Ellison, for the Appellant. Mr C Newton, Counsel, instructed by Hayes Gabriel Solicitors, for the Second Respondent. Mr P O'Neill, Counsel, instructed by the Workers' Compensation Regulator, the First Respondent. -- 1 of 13 -- 2 Decision Introduction [1] Clermont Coal Operations Pty Ltd ("Clermont Coal") appeals a decision of the Workers' Compensation Regulator ("the regulator") in which the regulator set aside an earlier decision of Glencore Queensland Limited (the self-insurer) to decline to accept an injury reported by Mr Paul Ebsworth and described as an annular tear said to have been sustained at work on 10 April 2015. [2] This was the second claim made by Mr Ebsworth arising from the performance of his work duties on 10 April 2015. His initial claim, which was an accepted claim, involved a lumbar spine injury described as an "aggravation of pre-existing degenerative spondylosis". [3] The annular tear was first identified in an MRI taken on 11 November 2015. Mr Ebsworth's injuries, including the MRI finding of an annular tear, were assessed by Dr Gillett on 14 January 2016. Dr Gillett entered a diagnosis of an injury to the lumbar spine associated with aggravation of degeneration and associated with annular tearing at the L4/5 disc. Mr Ebsworth subsequently lodged a claim with the self-insurer on 29 April 2016 for an injury described as "annular tearing of L4/5 disk". This injury was said to be associated with the accepted injury sustained on 10 April 2015. [4] The annular tear claim was rejected by the self-insurer on 9 May 2016. However, on review, the regulator set aside the self-insurer's decision, and determined that the claim was one for acceptance. It is this decision, which was dated 12 August 2016, that is now subject to appeal. Nature of Appeal [5] The appeal to the Commission is conducted by way of a hearing de novo. The questions to be answered in the determination of the appeal are: (i) Whether Mr Ebsworth's employment was a significant contributing factor to the annular tear claimed by Mr Ebsworth to have been sustained in an acute event at work on 10 April 2015; (ii) Whether Mr Ebsworth sustained an annular tear injury that was separate from his earlier accepted claim for "aggravation of degenerative spondylosis". [6] The effect of Dr Winstanley's evidence was that the annular tear was not related to employment. It was his opinion that the annular tear would not have been caused by an acute event at work and he favoured an outcome that the tear was a product of the degenerative processes. In the absence of a determination to prefer Dr Winstanley's evidence, the appeal turns on Dr Gillett's evidence that the annular tear was more likely to be considered a separate injury and related to employment if the acute event described by Mr Ebsworth did, in fact, occur. [7] The medical evidence established that the annular tear could have been sustained in the following circumstances: -- 2 of 13 -- 3 (i) The tear was caused by an acute event on 10 April 2015; (ii) The tear was caused by jolting and jarring of the lumbar spine over a period of time; (iii) The tear was associated with Mr Ebsworth's degenerative pathology, and unrelated to events at work. [8] While Dr Winstanley accepted that the annular tear could have been caused by jolting and jarring of the lumbar spine arising from dozer operations in the week commencing 7 April 2015, Mr Ebsworth's claim for compensation does not rest on such a premise. It is therefore unnecessary to include this scenario in the determination to be made about causation. Consequently the question to be answered is whether the annular tear was caused by an acute or traumatic incident at work on 10 April 2015. Legislation [9] The appeal will be resolved by reference to s 32 of the Workers Compensation and Rehabilitation Act 2003 (the Act) which relevantly provides: "32 Meaning of injury (1) An injury is personal injury arising out of, or in the course of, employment if— (a) for an injury other than a psychiatric or psychological disorder— the employment is a significant contributing factor to the injury; … (3) Injury includes the following— (a) a disease contracted in the course of employment, whether at or away from the place of employment, if the employment is a significant contributing factor to the disease; (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 to the aggravation— (i) a personal injury other than a psychiatric or psychological disorder; (ii) a disease; (iii) a medical condition other than a psychiatric or psychological disorder, if the condition becomes a personal injury or disease because of the aggravation; … (4) For subsection (3)(b) and (ba), to remove any doubt, it is declared that an aggravation mentioned in the provision is an injury only to the extent of the effects of the aggravation. …" -- 3 of 13 -- 4 The Accepted Injury [10] Mr Ebsworth had been employed by Clermont Coal since 1 February 2014 in the capacity of dozer operator. While Mr Ebsworth claimed that his injury occurred at work on 10 April 2015, he did not report his injury to his employer and completed his normal work shifts on 11, 12 and 13 April 2015 before returning home on a scheduled leave rotation at the end of his shift on 13 April 2015. [11] The appellant first sought treatment for his injury from his general practitioner, Dr Woodhouse, on 14 April 2015. A CT scan was commissioned and, on review on 15 April 2015, Dr Woodhouse recommended treatment with anti-inflammatory medication and physiotherapy. He issued a workers' compensation medical certificate on 27 April 2015, and Mr Ebsworth lodged his workers' compensation claim on 29 April 2015. In a review decision dated 9 October 2015, Mr Ebsworth's application for compensation was ultimately accepted as a lumbar spine injury described as an "aggravation of degenerative spondylosis". [12] The reasons for the decision of the regulator which is now subject to appeal (dated 12 August 2016) allude to the mechanism of injury for the accepted claim in the following terms: "You lodged a handwritten application, dated 29 April 2015, with Glencore for a 'Lower Back' and 'Right Hip' injury said to have been sustained on 10 April 2015 and caused as a result of 'operating a dozer with worn tracks .. operating of the dozer extremely ruff [sic] … worn state of the tracks … affected the smooth operation of the machine'." The Annular Tear [13] The annular tear was discovered when Dr Winstanley reviewed an MRI scan performed on 11 November 2015. While noting the finding in his report dated 13 November 2015 (Exhibit 12), Dr Winstanley did not express an opinion about the cause of the tear. He recorded the MRI findings as follows: "This shows no evidence of nerve root compromise. There is facet joint degeneration associated with the L4/5 and L5/S1 levels. There is a small annular tear present at the L4/5 level." [14] It is not in dispute that, in the absence of an MRI taken immediately prior to 10 April 2015, it is not possible to determine whether the annular tear occurred on 10 April 2015; whether the annular tear was present prior to 10 April 2015; or whether the annular tear occurred some time between 10 April 2015 and 11 November 2015. The effect of the medical evidence was that the annular tear may have been caused by an acute event or may have occurred as part of the degenerative process in which the annulus also degenerates and tears. [15] Dr Gillett included the annular tear in a diagnosis that he entered on 14 January 2016 after an examination of Mr Ebsworth. In a report written on 14 January 2016 (Exhibit 2), Dr Gillett expressed his diagnosis in the following terms: -- 4 of 13 -- 5 "The diagnosis is an injury to the lumbar spine associated with aggravation of asymptomatic degeneration in the lumbar spine associated with annular tearing at the 4/5 disc." [16] The nature of the association between the aggravation, the degeneration and the annular tear was explained by Dr Gillett in a supplementary report dated 27 April 2016 (Exhibit 3). In this report, Dr Gillett stated that the link between the degeneration and development of the annular tearing is that, as part of the degenerative process, the annulus also becomes degenerate and can tear. In a further report written by Dr Gillett on 27 June 2015 (Exhibit 5) he stated that an annular tear could be caused by either degeneration or a traumatic event. [17] Dr Winstanley said that the current view, informed by MRI scans in the normal population, was that annular tears are generally associated with the "wear and tear type process which occurs within the disc" (T3-14). While Dr Winstanley accepted that acute annular tears could occur, and that acute annular tears were more likely to be associated with degenerative discs, it was his evidence that, had Mr Ebsworth sustained an acute annular tear he would not have been able to continue to work on the days following the incident (T3-21): "An acute annular tear, in my experience, isn’t something that usually allows people to do activities such as driving a dozer on the next day. Their pain is too great, associated with muscular spasms." [18] Dr Winstanley accepted that it was possible that jarring and jolting experienced while operating a dozer over time could give rise to an annular tear. However, while he also accepted that it was possible that jolting and jarring of the spine over the course of a day might cause a minor and pre-existing annular tear to worsen and become more painful, he considered that this set of circumstances gave rise to the least likely scenario. [19] Dr Gillett opined that while the tear in Mr Ebsworth's annulus may have been part of a degenerative process in an asymptomatic disc, it was reasonable to suggest that the tear was caused by an incident at work on 10 April 2015, because the incident caused pain. In his evidence in the proceedings, Dr Gillett accepted that this opinion had been informed by the reporting of an acute event by Mr Ebsworth during the 14 January 2016 assessment. [20] The effect of the medical evidence was that acceptance of Mr Ebsworth's claim for compensation relied on Dr Gillett's evidence being preferred to the evidence of Dr Winstanley. Dr Gillett's support however was not unconditional. He accepted that if the history of an acute event given to him by Mr Ebsworth was not correct, then the annular tear may not be related to work activities (T2-14): "But I’m right, though, Doctor, in saying that in giving your opinion as to the probable cause of the annular tear as distinct from the rest of the pathology in Mr Ebsworth’s lumbar spine, that you rely on the reporting of this acute incident informing that opinion?---I think it’s a highly weighted event. [21] It was in these circumstances that the veracity of the history of causation provided by Mr Ebsworth was disputed by the appellant. It follows that the fate of the appeal -- 5 of 13 -- 6 hinges on whether Mr Ebsworth's version of events associated with an alleged acute event at work on 10 April 2015, is accepted or rejected. Mechanism of Injury – Contemporaneous Medical Records [22] Mr Ebsworth first sought treatment for his injury from his general practitioner, Dr Woodhouse, on 14 April 2015. According to the consultation notes of the visit, the appellant reported inter alia that he had hurt his back at work while driving his dozer, that he had not experienced any significant back pain prior to the work incident, and that he had not previously experienced similar pain. The notes indicated that the appellant experienced pain at "every bump and turn" and included the following entry: "dozer tracks worn – increased jolting and vibration and turning big jolts – almost impact". [23] Given that Dr Woodhouse was not called to give evidence, I am left to my own devices in terms of assigning a meaning to the entries in the medical records. In my view the entries should be construed to mean that worn tracks on the dozer caused increased jolting and vibration and that the jolting was more severe when the dozer changed direction. I do not know what the words "almost impact" refer to, but it must follow that if an impact was possible, it did not eventuate. [24] The self-insurer referred Mr Ebsworth to Dr Winstanley for assessment on 26 May 2015. In his report dated 29 May 2015 (Exhibit 11), Dr Winstanley recorded the history provided by Mr Ebsworth in the following terms: "Mr Ebsworth has developed symptoms while working on a dozer at the Clermont Coal Mine on 10 April 2015. He was working on a rocky area. The dozer which he was working on had worn tracks which increases the shock to the driver. He developed symptoms in his lumbar spine on 10 April 2015 at the end of his shift. He finished early on that day. He returned to work the following day with discomfort in his lumbar spine and right hip area. He gives a description of right buttock and upper thigh pain. Mr Ebsworth describes no groin discomfort. He was able to complete two further days of work on a new machine which had better tracks, with ongoing pain in his lumbar spine." [25] In terms of the most contemporaneous reporting of the event, the account provided by Mr Ebsworth to both Dr Woodhouse and Dr Winstanley does not identify any particular causative event but rather creates an impression of pain caused or brought on by operating a dozer with worn tracks in rough conditions. These circumstances led to increased vibration, shocks or jolting of the operator. The impression is of an adverse cumulative impact on the lumbar spine over time, not of a single traumatic event. [26] The history recorded by Ms Korman also characterised an over time injury caused by operating a dozer in rough conditions. Mr Ebsworth attended on Ms Korman on 2 November 2015. Her notes of this consultation (Exhibit 16) include the following: -- 6 of 13 -- 7 "Plant operator. Heavy machinery. Back injury. 14th, the 4th, 2015. Operating a bulldozer. Tracks were not good. Bouncing over rocks for a week on it. Didn’t report initially. Week on, week off. Thought it would come good during his week off. " [27] The self-insurer arranged for Mr Ebsworth to be assessed by Dr Yoxall on 27 November 2015. Dr Yoxall's report dated 22 December 2015 (Exhibit 14) included a thorough history associated with the development of physical symptoms which included the following information, or information to this effect:  Mr Ebsworth said that after four days on this particular dozer and the nature of the job he was doing, his back did not recover as it normally would after a stretch.  Mr Ebsworth said that on Friday 10 April 2015 he was on a busy dump and the material that he was pushing around was very rocky material. Some of the rocks were the size of small cars. He said that the tip-head ranged from 'nothing' to approximately twenty metres high and he was 'bouncing over rough stuff all day'.  Mr Ebsworth said that he was operating a dozer with excessively worn tracks, which would not absorb the shock out of the job. He said that he had been on this dozer all week. He said that in order to steer the dozer, one track stops and the other one turns. He said that when the dozer was turning, the track was 'snapping', throwing dirt off the track as high as the bonnet.  Mr Ebsworth said that the particular job that he was doing on Friday 10 April 2015 aggravated his lower back. He said that the symptoms were pain in his lower back and in the right hip region. He said that by 5pm he could not continue to work because of the pain.  He said that he called his Supervisor, Mr Hayes and reported the worn tracks. He said that Mr Hayes suggested that Mr Ebsworth park the dozer, and call up the fitters. Mr Ebsworth confirmed that this was about 2 hours before he was supposed to finish his shift. He confirmed that he did not report any physical injury to Mr Hayes at that time.  Mr Ebsworth said that he left the workplace without reporting his symptoms of pain in his lower back and right hip symptoms to anyone. However, he said that he did mention his physical discomfort to a few other workmates in the previous days. [28] Again, consistent with previous reporting, Mr Ebsworth has described an injury resulting from the effects on his spine of operating his dozer in rough conditions over a number of days and culminating in an increased level of pain or discomfort which caused him to stop work early on 10 April 2015. However despite a very detailed history being taken by Dr Yoxall, Mr Ebsworth provided a significantly different version of events to Dr Gillett only six weeks later. -- 7 of 13 -- 8 [29] Mr Ebsworth had been referred to Dr Gillett for assessment by his lawyers. He attended on Dr Gillett on 14 January 2016. It was at this consultation that Mr Ebsworth informed Dr Gillett about a specific incident that occurred at work on 10 April 2015. This history is recorded in Dr Gillett's report dated 14 January 2016 (Exhibit 2): " On 10 April 2015 the claimant advises that he injured his lower back whilst operating a D11 large mine dozer. He states that the tracks were "buggered" and he was operating it over rocky terrain. He was bouncing on the terrain and the tracks wouldn't work properly. Turning was an issue. It was very rough riding. There was constant jarring associated with it. He advises me that it reached a point that he parked the dozer about 5.00 pm. He commenced the shift at 6.30 am. At 5.00 pm he contacted the shift supervisor to advise that there was a problem with the machine and he was told to contact the maintenance people. He was then swapped out of the shift. He then worked the following three days on a different machine with progressive increasing pain in his lower back. He then travelled from Clermont to the Emerald Airport on the evening of 13 April 2015. The bus ride was about an hour and a half which increased his pain and then he returned to his home at Noosa on the evening of Monday, 13 April 2015 and subsequently saw his General Practitioner the next day. In relation to the work practice on the day that he developed the pain he states that he recalls one episode before the second smoko where he went over a rough spot and the vehicle went down hard. He was reversing at the time. There was a hard bang. He is not sure if the seat bottomed out but he recalls it going down hard. He was aware of pain. The pain persisted the rest of the shift." [30] This was the first occasion that Mr Ebsworth identified a specific or acute incident when addressing causation or the mechanism of injury. In this respect, Mr Ebsworth did not deny that he had not previously reported the existence of an acute incident. It was his evidence that despite the significance of the incident which occurred during the operation of the dozer on 10 April 2015, and despite the fact that he had been pain free on the day of the incident, he only recalled the incident because Dr Gillett had specifically questioned him about the existence of such an event, and in circumstances where prior to this, no one had prompted him to recall such an incident. Mechanism of Injury – Lay Evidence [31] In his evidence in the proceedings, Mr Ebsworth said that he first experienced pain on 10 April 2015 when he reversed back over a very large rock and the machine "went up pretty high and then crashed down hard". He said however that he continued to work, but it got to a point where he could not operate the machine any more, and that around 5.00 pm he called Mr Hayes and parked up his machine. Mr Ebsworth said that between 10 April 2015 and 13 April 2015 when he left the site, his back was very painful and that the pain got worse over time. Despite significant and worsening pain he was able to continue to work on 11, 12 and 13 April 2015 because he took things easy and he was given a different dozer to operate. [32] Mr Ebsworth failed to provide any consistent account about when the 10 April 2015 incident occurred. What is not in dispute is that he stopped work at or about 5.00 pm -- 8 of 13 -- 9 on 10 April 2015 after contacting Mr Hayes and complaining about the condition of his dozer's tracks. While he did not tell Mr Hayes that he was experiencing pain, he told Dr Winstanley on 26 May 2015 that he developed symptoms at the end of his shift and that he finished work early on that day (10 April 2015). [33] When Mr Ebsworth first raised the incident at work with Dr Gillett, he said that the incident occurred before his second crib break. The machine log, which is in the evidence as Exhibit 18, shows that Mr Ebsworth's second crib break on 10 April 2015 commenced at 3.00 pm, while his first crib break ended at 11.21 am. If the incident happened before the second crib break, then it must have occurred between 11.21 am and 3.00 pm. [34] However, during cross examination Mr Ebsworth accepted that the incident could have occurred before the first smoko. Mr Ebsworth appeared to accept this scenario because it fitted with Mr Bensemann's account that he complained about back pain during the first crib break. Mr Bensemann's account of pain could not have been true if the incident occurred after the first crib break and in circumstances where Mr Ebsworth said he did not experience any pain on the day until the incident. The end result of this flexible approach to the facts, was that the alleged incident could have occurred at any time up to about 5.00 pm in the afternoon. [35] Mr Hayes was a mining supervisor at Clermont Coal. He was Mr Ebsworth's supervisor. It was his evidence that Mr Ebsworth did not raise any concern about the operation of his dozer nor the presence of any operational hazards on 7, 8, and 9 April 2015. However on 10 April 2015 at around 9.00 am Mr Ebsworth called Mr Hayes on the two-way radio and reported that something was wrong with the tracks on his dozer. As a consequence, Mr Hayes arranged for a leading hand, Mr Wolstenholme, to conduct an assessment of the dozer. As a result, Mr Wolstenholme relieved Mr Ebsworth during Mr Ebsworth's crib breaks, to inspect the condition of the dozer's tracks and to test drive the dozer. After the breaks, Mr Ebsworth resumed duties on the dozer. [36] Mr Hayes did not subsequently interact with Mr Ebsworth until 5.30 pm that afternoon when Mr Ebsworth again called him on the two-way radio and told him that there was still an issue with the dozer. The effect of Mr Hayes's evidence was that while Mr Ebsworth complained about the dozer tracks, he did not say anything about back pain nor did he report or allude to any hazardous incident. While Mr Hayes said he believed that the area that Mr Ebsworth was working in was in good condition, he accepted in cross-examination that in giving this evidence he was not relying on contemporaneous notes, but was relying on his memory to inform him of the condition of the dumps (some 12 months earlier), and that his memory may be unreliable. [37] Mr Wolstenholme had been a leading hand for Clermont Coal for about three years. He reported to Mr Hayes. Mr Wolstenholme had completed an Incident Witness Statement on 3 June 2015. In this statement (Exhibit 17) Mr Wolstenholme said that Mr Ebsworth had informed him that Dozer 482 was running "rough" and that the right track was a "little loose". He said that he inspected the tracks but found that they were within operating specifications. He said that he operated Dozer 482 for approximately 1.5 hours during the relief periods and that he found the dozer to be "no rougher than any other dozer we use". -- 9 of 13 -- 10 [38] In his evidence in the proceedings, Mr Wolstenholme said that on 10 April 2015 he was asked by Mr Hayes to relieve Mr Ebsworth on Dozer 482 during periods when Mr Ebsworth was on a crib break. Mr Hayes told him that Mr Ebsworth had reported that the dozer was running rough. According to Exhibit 18, the reliefs occurred between 10.26 am and 11.21 am, and between 3.01 pm and 4.00 pm. [39] Mr Wolstenholme said that when he relieved Mr Ebsworth, Mr Ebsworth told him that the machine was rough and that the right hand track may be loose or worn. Mr Ebsworth said that the machine was rough to sit in and according to Mr Wolstenholme, he seemed "a little bit concerned". Mr Ebsworth did not tell Mr Wolstenholme that he was suffering pain or that his machine had been involved in a particular incident or incidents. [40] Mr Wolstenholme said that when he relieved Mr Ebsworth on Dozer 482 he had completed a pre-start check of the vehicle and found no significant problem. In terms of the condition of the area where the dozer was to operate, it was Mr Wolstenholme's evidence that basalt rocks about a metre in width could be encountered, but the manouvre was to clear the rocks by pushing them over the tip head. He denied that the rocks were as big as small cars. Notwithstanding this, Mr Wolstenholme conceded that the condition of the dump varies, and that the material he was moving during his relief of Mr Ebsworth could have been quite different to the material that Mr Ebsworth would have been moving. [41] After his first relief on dozer 482, Mr Wolstenholme told Mr Hayes that he did not have any difficulty with the operation of the machine, and said that he had told Mr Ebsworth that if he experienced any difficulty with the dozer he should get the mechanical tradesmen to inspect the machine. Mr Wolstenholme did not have any recollection of matters relating to his second relief. [42] Mr Bensemann recalled taking a crib break at the same time as Mr Ebsworth on a day understood to be 10 April 2015. He said that the break was taken some time between 9.30 am and 11.00 am. He said that during the break Mr Ebsworth told him that he had a sore back and that he attributed the cause of his sore back to the operation of his dozer. Mr Bensemann also said the Mr Ebsworth told him that he had a sore back during the second crib break on the same day which would have been taken some time between 2.00 pm and 4.30 pm. [43] Mr Bensemann could not recall whether Mr Ebsworth had told him how he hurt his back, nor did he recall Mr Ebsworth attributing the sore back to a specific incident at work where he reversed a dozer over a big rock. He said that Mr Ebsworth did not show any visible signs of pain. [44] Mr Bensemann was also on the same bus as Mr Ebsworth on the trip from the mine site to Emerald airport on 13 April 2015. On this occasion Mr Bensemann said that he overheard Mr Ebsworth complaining to someone about the bus ride being rough and saying that he had a sore back. [45] Mr Bensemann had driven dozers on the mine site including Dozer 482. He said that he did not have a problem when he was operating any of the dozers. He said that he would have operated Dozer 482 within a six week period prior to 10 April 2015. He confirmed however that if the tracks were worn the machine could cause a jarring -- 10 of 13 -- 11 effect for the operator. He also said that it was "a pretty common thing" for a dozer reversing over a big rock to come down hard. Conclusion [46] Mr Ebsworth did not raise nor rely on the existence of any significant precipitating event when he made his initial application for workers' compensation, nor when he reported his injury to his general practitioner on 14 April 2015 or to Dr Winstanley on 26 May 2015. None of the history provided to medical practitioners or psychologists throughout 2015 included reference to a significant causative incident. Rather, the mechanism of injury appeared to be characterised by increased operator jolting and jarring caused by worn tracks and rough operating conditions, most probably encountered in the period from 7 April 2015 to 10 April 2015. [47] Mr Ebsworth's explanation for providing a different version of events to Dr Gillett on 14 January 2016 is implausible. It is very unlikely that particulars about causation or the mechanism of injury would not have been sought by his general practitioner and Dr Winstanley. Dr Winstanley in particular, in conducting a workers' compensation assessment, could have been expected to be specifically interested in the mechanism of injury. The history taken by Dr Yoxall is also relevant. It is unlikely that, despite the painstaking manner that Dr Yoxall had elicited and recorded the history associated with the physical injury, Mr Ebsworth would not have recalled and recounted the one "stand-out" event in a week of rough conditions and persisting jolting and jarring. [48] Had a specific traumatic event occurred which caused pain on a day when he was otherwise pain free, on balance, Mr Ebsworth could have been expected to inform Dr Woodhouse and Dr Winstanley. In waiting until January 2016 to introduce the event, Mr Ebsworth has attempted to rewrite history by embellishing a factual matrix in which back pain did not result from a specific traumatic event, but occurred as symptoms progressively developed and increased over time until Mr Ebsworth stopped work an hour or so early on 10 April 2015. [49] The foundation for the factual matrix is drawn from the contemporaneous medical reports. In the first instance, Mr Ebsworth told Dr Woodhouse that he experienced pain "at every bump and turn"; told Ms Korman that he was "bouncing over rocks for a week on it"; and told Dr Yoxall that he was "bouncing over rough stuff all day". Secondly, he told Dr Winstanley that operating a dozer with worn tracks in these conditions increased the shock to the driver, and caused him to develop symptoms toward the end of his shift on 10 April 2015. Thirdly, he told Dr Yoxall that after operating in rough conditions for four days on Dozer 482, his back did not recover as it normally would. All these propositions suggest conditions persisting over time that contributed to, or caused, Mr Ebsworth's injury, and diminish the likelihood that an acute event has occurred. [50] A series of inconsistencies undermines Mr Ebsworth's version of events. Despite complaining about worn tracks to Mr Hayes on two occasions on 10 April 2015 he did not report an injury, any specific incident, nor the presence of back pain. Further, despite Mr Wolstenholme relieving him on two occasions on 10 April 2015, he did not say anything to him about a specific incident or about back pain. While he told Mr Bensemann at both crib breaks on 10 April 2015 that he was experiencing back pain, he did not say anything to Mr Bensemann about any particular incident causative of -- 11 of 13 -- 12 the back pain. Finally, Mr Ebsworth demonstrated in his evidence that he had no reliable recollection of when the alleged acute event occurred. [51] There is also a basic inconsistency in the narrative introduced by Mr Ebsworth post 14 January 2016. At the heart of the inconsistency is the complaints made about worn tracks and the emphasis on this factor as the basic or underlying cause of his back injury. [52] During the course of operating dozer 482 on 7, 8, 9 and 10 April 2015, Mr Ebsworth said that he had he complained about worn dozer tracks to several people on one or more occasions. He said that he discussed the tracks with a serviceman, Steve Fogarty, on 8 April 2015 and with Stewart Forsyth, a fitter, on 9 April 2015. He said that Mr Wolstenholme had relieved him during his crib breaks over this period and that he had raised the conditions of the tracks with him on three occasions, on at least two different days. He said he told Mr Wolstenholme that operating the dozer in rough, rocky conditions was like riding a bull. Further, he said that he told Mr Hayes about the tracks the day before the incident, as well as reporting them to him on 10 April 2015. [53] On the one hand, back pain was caused by worn tracks and rough operating conditions which prevailed over the course of the week. On the other hand, despite the rough conditions and the poor tracks, Mr Ebsworth was pain free on 10 April 2015 until a significant incident, unrelated to the condition of his dozer tracks, intervened and caused immediate pain. In his evidence, Mr Ebsworth was unable to explain the apparent contradiction (T1-57): "See, this incident you described, I’d suggest to you, given you went over this huge rock, and then have come down hard, the tracks wouldn’t have been a factor in that incident, would they? How are the tracks relevant to that incident where you’ve - - -?---You’d – I’m not – that machine was rough. It wasn’t – it wasn’t taking the shock as it should’ve done on the rough dump. And that’s really probably a question for someone who specialises in the maintenance of the things. But - - - Well, you – you were - - -?---I was an operator. And it was operating rough, very rough. If the tracks had’ve been in good working order, or good condition, the operation of the machine wouldn’t have been as rough. Would it have stopped that injury to my back? I don’t know. I can’t answer that." Decision [54] The evidence supports a finding that it was more probable than not that Mr Ebsworth's injury was caused by persistent jolting and jarring experienced by the dozer operator over a period of days commencing on 7 April 2015. The evidence does not support a finding that a significant traumatic event occurred on 10 April 2015. [55] In terms of the medical evidence, Dr Winstanley's preferred view was that the annular tear was a product of degeneration, while Dr Gillett's evidence was that, if a specific traumatic event did not occur, the annular tear could not be distinguished from the rest of the pathology in Mr Ebsworth's lumbar spine. This means that either the annular tear was a product of degeneration and unrelated to work, or it could not be treated as an injury separate from the injury that was the subject of the accepted claim. -- 12 of 13 -- 13 [56] The appeal is allowed. The regulator's decision dated 12 August 2016 is set aside and replaced with a decision to the effect that the claim is not one for acceptance. The matter of costs is reserved. [57] I order accordingly. -- 13 of 13 --