Coles Supermarkets Australia Pty Ltd v Simon Blackwood (Workers' Compensation Regulator) [2015] QIRC 11

QUEENSLAND INDUSTRIAL RELATIONS COMMISSION CITATION: Coles Supermarkets Australia Pty Ltd v Blackwood [2015] QIRC 011 PARTIES: Coles Supermarkets Australia Pty Ltd (Appellant) v Simon Blackwood (Workers' Compensation Regulator) (Respondent) CASE NO: WC/2013/313 PROCEEDING: Appeal against decision of the Workers' Compensation Regulator DELIVERED ON: 20 January 2015 HEARING DATES: 18 and 19 March 2014 MEMBER: Industrial Commissioner Neate ORDERS : 1. The Appeal is allowed. 2. The decision of the Regulator dated 30 August 2013 is set aside and substituted with a decision that the claim by Brendan Peter Short is not 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 the subject of a further application to the Commission. CATCHWORDS: WORKERS' COMPENSATION - APPEAL AGAINST DECISION - worker injured by fall at work - fractures to L3 and 6th rib healed gradually - L5/S1 disc prolapse identified more than three months after fall - compensation terminated - second compensation claim based on L5/S1 prolapse - claim accepted by Regulator - whether injury arose out of or in the course of employment - whether employment was a significant contributing factor to the injury - conflicting expert evidence - Appellant bears onus of proof. CASES: Adelaide Stevedoring Company Ltd v Forst (1940) 64 CLR 538 -- 1 of 29 -- 2 Chattin v WorkCover Queensland (1999) 161 QGIG 531 Commissioner of Police v David Rea [2008] NSWCA 199 EMI (Australia) Limited v Bes (1970) 44 WCR 114 Fernandez v Tubemakers of Australia Ltd [1975] 2 NSWLR 190 Holtman v Sampson [1985] 2 Qd R 472 Joyce v Yeomans [1981] 1 WLR 549, [1981] 2 All ER 21 Monroe Australia Pty Ltd v Campbell (1995) 65 SASR 16 Obstoj v Van de Loos (Unreported, Supreme Court of Queensland, Connolly J, 16 April 1987) Gaudry v Pacific Coal P/L [1996[ QCA 525 Qantas Airways Ltd v QComp (2006) 181 QGIG 301 Ramsay v Watson (1961) 108 CLR 642 Rossmuller v Q-COMP (C/2009/36) - decision http://www.qirc.qld.gov.au Sotiroulis v Kosac (1978) 80 LSJS 112 State of Queensland (Queensland Health) v QComp and Beverley Coyne (2002) 172 QGIG 1447 APPEARANCES: Ms J McClymont, counsel instructed by Minter Ellison Ms D Callaghan, counsel directly instructed by the Workers' Compensation Regulator Decision [1] Coles Supermarkets Australia Pty Ltd ("the Appellant") has appealed under s 550 of the Workers' Compensation and Rehabilitation Act 2003 ("the Act") against the decision of the Workers' Compensation Regulator ("the Respondent") dated 30 August 2013 to set aside the decision of Coles Group (Wesfarmers), a self- insurer for the purposes of the Act, to reject an application for compensation dated 19 April 2013 by Brendan Peter Short. Mr Short made a claim for compensation in relation to L5/S1 disc protrusion, which he alleged occurred as a result of a fall on 28 June 2012 in the course of his employment. [2] Section 32(1) of the Act provides, in part: "(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] The parties do not dispute that Mr Short: (a) was a "worker" under the Act; and -- 2 of 29 -- 3 (b) suffered a medical condition being a L5/S1 disc prolapse. [4] The only issues in this case are whether: (a) Mr Short's L5/S1 disc protrusion arose out of or in the course of his employment with the Appellant, specifically as a result of the fall on 28 June 2012; and (b) his employment (specifically the fall on 28 June 2012) was a significant contributing factor to the injury. [5] The appeal is a hearing de novo, and the Appellant bears the onus of proof.1 For the appeal to succeed, the Appellant must satisfy the Commission that, on the balance of probabilities, the L5/S1 disc protrusion for which Mr Short claimed compensation was not an "injury" pursuant to s 32 of the Act. [6] The evidence before the Commission includes oral evidence from Mr Short about the fall and the nature and extent of his symptoms following his fall, oral evidence from Mr Short's partner (Liam McDonogh), evidence from two employees of the Appellant (Kimberley Hart and Jennifer Bateman), and expert medical evidence from Mr Short's general medical practitioner (Dr Bak Ching Ng) and two orthopaedic specialists (Associate Professor Richard Williams and Associate Professor Howard Kerry Outerbridge). The circumstances of Mr Short's fall on 28 June 2012 [7] Mr Short commenced employment by the Appellant from November 2011 as a delivery driver. That work included collecting crates and loading them onto a truck for delivery to customers. There would be an average of six or seven crates per delivery and sometimes items for between 18 and 21 deliveries would be loaded onto a truck for one shift. The content of crates varied and they could weigh up to 20 or 25 kg. At a customer's premises, crates would be either transported by trolley or carried. The crates would be taken into the customer's house and emptied. The empty crates would then be returned to the truck. [8] In the period from November 2011 and June 2012, Mr Short experienced back pain "very rarely", and any such pain was light muscular pain from the rigours and the physical nature of the job. During that period, Mr Short used to ride his bicycle, go running, walk his dog, do gardening and undertake modifications to his car. [9] On Thursday 28 June 2012, Mr Short was delivering groceries at a customer's house. At the hearing, he gave the following evidence: 1 State of Queensland (Queensland Health) v QComp and Beverley Coyne (2002) 172 QGIG 1447; Qantas Airways Ltd v QComp (2006) 181 QGIG 301. -- 3 of 29 -- 4 "I went via the back steps and was carrying some crates down the steps and slipped and fell on my lower back, and my lower back hit the edge of the step and the crates came down on my chest."2 [10] Mr Short said that he experienced pain in his chest area and pain in his lower back. Having delivered the groceries, he returned to his truck and called his supervisor. A senior team member was sent to pick him up. After completing the delivery they went to the Princess Alexandra ("PA") Hospital where Mr Short was assessed by a triage nurse who advised him to take some Panadol and go home and rest. He was told there would be an 11 hour wait to see doctors. Because it was late at night, he elected to go home. Mr Short first saw a doctor, a general practitioner, on 30 June 2012. Mr Short's first compensation claim [11] On 3 July 2012, Mr Short completed an Employee's Application for Compensation which was received by Wesfarmers Group WorkCover Qld ("Wesfarmers") on 4 July 2012 (Exhibit 1). That Application stated that the injury occurred at 6:30 pm on Thursday, 28 June 2012 as follows: "Walking down painted concrete steps. Holding 1 crate. Slipped and landed on my back." The injury was described as "Back Injury" and was to the "Lower left" of his back. [12] On 4 July 2012, Mr Short contacted Claims Management at Wesfarmers. Ms Hart entered a record of the conversation (Exhibit 3) including the following: "- MOI - hard to tell for sure as the CSA are out on private properties but W[orker] reported that he had delivered groceries when he went to walk back and slipped down the steps and landed on back and wrist - w[orker] went to the PA hospital but couldn't get to see a dr because of the wait so went to the dr two days later on 30/6. 29/6 will be lost now - TI cert 29/6-3/7 - review this week, probably waiting on x-ray results first. - Perm part time - no issues with claim. CO adv[ised] - need to speak to w[orker] to confirm information but likely claim acceptance for time lost and medical expenses - CO to confirm and send acceptance letters." Treating Mr Short's injury and subsequent events [13] The symptoms described by Mr Short, the tests administered and the treatment provided by various doctors, and the observations and diagnoses of those doctors can be traced through Mr Short's patient medical history (Exhibit 10), workers' compensation medical certificates (Exhibit 11) and other records in evidence. In his oral evidence, Mr Short's usual general medical practitioner, Dr Ng, explained some of the abbreviations and notations in Exhibit 10. The salient aspects for this case are set out in chronological order below. 2 Transcript of Proceedings, Coles Supermarkets Pty Ltd v Simon Blackwood (Workers' Compensation Regulator) (Queensland Industrial Relations Commission, WC/2013/313, Industrial Commissioner Neate, 18 March 2014) 22. -- 4 of 29 -- 5 [14] On Saturday 30 June 2012, Mr Short attended the Medical and Dental Centre ("MDC") at Blunder Road, Oxley. His medical history notes that he slipped on concrete stairs and landed on his back late on Thursday evening. At that time, Mr Short was taking Voltaren Rapid (a pain killing drug that also reduces inflammation) and Ibuprofen (an anti-inflammatory drug). His medical history also includes an entry "Pain L lumbosacral area, yet R SLR most impaired" (Exhibit 10). Dr Farron Young made a provisional diagnosis of lumbosacral back injury, ordered x-rays of lumbosacral spine, and prescribed Panadeine Forte tablets (to relieve pain) and Feldene (an anti-inflammatory drug). [15] Mr Short was issued with a workers' compensation medical certificate dated 30 June 2012 which stated that he was unable to work at all from 29 June to 3 July 2012. [16] On Tuesday 3 July 2012, Mr Short attended the MDC and saw Dr Philip Stowell. The notes in his medical history include: "pain continues and quite sore XR results … marked bruise over L[eft] Ileum and marked reduction in ROM [range of movement]… flex 50% pain over bruise Lat flex R& L 25 Rotation R > L and also more painful … gen dysfunctional movement does ride bike and walks XR unhelpful." Dr Ng's reading of these notes confirmed that the x-ray results were unhelpful, there was bruising on Mr Short's left side, and he had reduction in his movement. The notes also record some concern about the weight of delivery crates, which can weigh more than 20 kg, are quite large and bulky, and are hard to lift and carry on occasions. Dr Stowell issued a workers' compensation medical certificate stating that Mr Short was not able to work from 3 to 5 July 2012, and would be fit for restricted return to work from 6 to 16 July 2012. [17] A file note by Ms Hart of a conversation with the employer, entered on 11 July 2012 (Exhibit 3), indicates that Mr Short was performing suitable duties on his first day at work, Friday 6 July 2012. After about two hours he could not finish or go any further. He was prescribed heavy painkillers but was unable to take them whilst at work because of how strong they were. When he started moving around, the pain was too high. He was allocated work in an area where lifting was very light. Mr Short had been told to go to the GP on the Friday, Saturday but did not go until Tuesday. The notes indicated that there would be an attempt to contact Mr Short again and to get further information from his treating GP. [18] On Monday 9 July 2012, Mr Short attended the MDC and his medical history refers to: "low back pain/strain … PF not help -- 5 of 29 -- 6 digesic no help." He was issued with a workers' compensation medical certificate stating that he was not able to work from 10 to 12 July 2012. [19] On Friday 13 July 2012, Mr Short first consulted Dr Ng at the MDC. Dr Ng's notes for that visit state: "getting better has not work yet no bruise mild restriction lumbar rom, esp L lateral flexn, AP flexn/extension rotation normal return to suitable light duty 4 hr/day x 5 /wk." Dr Ng was aware that Mr Short was taking Voltaren and Ibuprofen at that time. Dr Ng issued a workers' compensation medical certificate stating that Mr Short was not able to work from 6 to 15 July 2012 but would be fit for a restricted return to work from 16 to 23 July 2012. [20] On Tuesday 17 July 2012, Mr Short attended the MDC and saw Dr Young. His medical history includes the following notes: "yesterday went back to work for 4 hr shift. Stiff after 3 hrs. Painful and stiff this morning. Stiffness main issue now Reduced ROM Muscle spasm. Red to 3 hrs/day PT referral. Get claim number from Coles." Dr Young issued a workers' compensation medical certificate that Mr Short was not able to work on 17 July 2012 but would be fit for restricted work from 18 to 20 July 2012. [21] On Sunday 22 July 2012, Mr Short attended the MDC and his medical history notes: "isq increased work says getting better unable to get physio apt:". He was issued with a workers' compensation medical certificate stating that he was fit for restricted return to work from 23 July to 3 August 2012 and required physiotherapy. [22] On Wednesday 25 July 2012, Mr Short attended MDC and saw Dr Ishak Ibrahim. His medical history notes: -- 6 of 29 -- 7 "back from work exacerbation of low back pains after work 5hrs/d physio t/m limted flexion no sciatica" (i.e., no evidence or clinical symptoms of a pinched nerve). Mr Short was issued with a workers' compensation medical certificate stating that he was not able to work on 25 and 26 July 2012, but would be fit for restricted return to work from 27 July to 5 August 2012. [23] On Thursday 2 August 2012, Mr Short attended the MDC in relation to a sore throat and cough. [24] After referral to a physiotherapist on 17 July 2012, Mr Short engaged in physiotherapy exercises. He attended the MDC on Friday 3 August 2012 for physiotherapy with Catherine Aganoff, and his medical history notes "Back is a bit better." [25] On Sunday 5 August 2012, Mr Short attended the MDC and Dr Ng noted: "physio 2x/wk still mild LBP [lower back pain], stiffness poor sleep, want Tamazepam no distress stiffness end of lumbar rom [i.e., when bending forward] good rom … suitable light duty 5 hr/day, 5x/wk." Mr Short was to continue physiotherapy and do exercises at home. Dr Ng said there was not much difference between Mr Short's condition on this occasion and 13 July 2012. Although his range of movement was good, Mr Short still had back pain and stiffness and trouble sleeping. Dr Ng issued a workers' compensation medical certificate stating that Mr Short was fit for a restricted return to work from 6 to 20 August 2012 and that he required physiotherapy. [26] The medical history notes that, apparently as a result of a telephone conversation with a woman at the Coles Group Injury Service, it was agreed to reduce Mr Short's workload from five hours to four hours each day that week. He was scheduled to have an independent medical examination a few weeks later. [27] On Wednesday 8 August 2012, Mr Short had a physiotherapy session at the MDC. His medical history reports that his back condition was "improving", but also included "L chest pain?" [28] A file note entered by Ms Hart on 14 August 2012 indicated that Mr Short was happy with an updated return to work plan and was "progressing well". He was using heat packs in break time which was helping, and was having ongoing physiotherapy. Among other things, "pain levels have decreased." (Exhibit 3) -- 7 of 29 -- 8 [29] Mr Short was subsequently treated by Dr Ng for a cough and cold, which he had for about three weeks. On Saturday 18 August 2012 his medical history includes the following entries: "R chest wall pain 1 wk, did not work yesterday back pain improved, tolerating 5 hrs/day work." Dr Ng explained that Mr Short experienced a dull soreness on the right side of his chest, and he continued to have physiotherapy. Dr Ng increased Mr Short's work to six hours per day for five days each week. Dr Ng issued a workers' compensation medical certificate stating that Mr Short was not able to work on 17 August 2012, but was fit for restricted work from 20 to 27 August 2012. [30] On 18 August 2012, Mr Short also had a physiotherapy session at the MDC. His medical history records "Lower back is feeling much better." It also states that he felt a sharp pain in the right side of his ribs/chest after reaching his arm up to do superman exercise one week earlier. Mr Short felt sharp severe pain in right chest wall since. [31] At the request of Wesfarmers, Mr Short attended on Associate Professor Williams on Monday 20 August 2012. In his report dated 19 September 2012 (the "first report"), Associate Professor Williams noted that Mr Short gave no prior history of low back pain. His current symptoms were described as follows: "He reports no lower back pain to any extent although he does describe some stiffness after a few hours at work. He does experience right sided upper chest pain in the region of the breast. He reports that if his pain level was 10/10 at the time of its onset, at worst now the pain approximates 8/10 in the breast area at worst and 3/10 at best. He reports that his lower back pain is all but resolved and is at worst 1/10 or 2/10 these days." (Exhibit 2) Associate Professor Williams also noted that Mr Short's "lumbar spinal pain was considered to be to the left side at L5 although it is not present currently" and that the right breast area was tender in the region of the 2nd and 3rd ribs just lateral to the mid-clavicular line. [32] On Wednesday 22 August 2012, Mr Short had a whole body bone scan with CT. [33] The first report refers to an ultrasound of the right breast and axilla on 20 August 2012 and a whole body bone scan on 22 August 2012. Having regard to the radiological imaging and his examination of Mr Short, Associate Professor Williams diagnosed that the right L3 transverse process fracture was "now resolved" and the right 6th rib fracture was "resolving." His prognosis was for eventual improvement in right breast symptoms based on the soft tissue nature of the injury. He continued: "I think it likely that the symptoms of the right fractured rib will dissipate with time. The symptoms in relation to the lumbar spine have already resolved and there is no predisposition for recurrent symptoms. -- 8 of 29 -- 9 I would think it likely at this stage that Mr Short could return to his usual activity, which is delivery driving, although he would perhaps gradually increase his weight tolerances, initially to 10 kg and then back to normal over a period of a further four weeks. He could undergo physiotherapy for a further six weeks before ceasing this treatment, in my opinion." [34] Associate Professor Williams also stated that: (a) Mr Short's symptoms relate to the employment-related fall and employment is therefore a significant contributing factor to the injury; (b) Mr Short's condition was improving and he would expect it to be "stable and stationary" in six weeks' time; (c) he considered it reasonable for Mr Short to return to full duties over a six week period. [35] On Thursday 23 August 2012, Mr Short attended the MDC for physiotherapy. His medical history notes include: "Pain in ribs still there but not as bad. LBP [lower back pain] is much better. Bone scan shows # 6th rib & L3 transverse process which are both clinically consistent." [36] That day Ms Hart received a phone call from Mr Short in which he advised, among other things, that he had a fracture of the 3rd vertebrae and his 6th rib was broken (Exhibit 3). [37] On Sunday 26 August 2012, Mr Short attended the MDC and was issued with a workers' compensation medical certificate that referred to the 6th rib and transverse L3 injury and stated that Mr Short was fit for restricted return to work from 26 August to 2 September 2012. [38] On Friday 31 August 2012, Mr Short attended the MDC for physiotherapy. His medical history includes the note that "Lower back is feeling ok just stiff. R rib area feels a bit sore and stiff." [39] On Wednesday 5 September 2012, Mr Short attended the MDC. Dr Ng referred to the results of the bone scan and noted "getting better … good mobility," which he said meant that Mr Short's back was moving quite well at that time. He also noted that Mr Short was suitable for "light duty 6 hr/day x 5/wk." Dr Ng issued a workers' compensation medical certificate stating that Mr Short was fit for restricted return to work from 3 to 16 September 2012. [40] Mr Short saw Dr Ng on Friday 7 September 2012 in relation to chest wall pain. He also had a cough. Mr Short was not at work on 6 and 7 September 2012. Dr Ng issued a workers' compensation medical certificate stating that Mr Short was not able to work from 6 to 7 September 2012, apparently due to exacerbation of chest wall pain, but would be fit for restricted return to work from 10 to 16 September 2012. -- 9 of 29 -- 10 [41] Mr Short saw Dr Ng on Monday 10 September 2012 in relation to a chest wall pain. He had cough and lower chest wall pain. Dr Ng ordered an x-ray and issued a workers' compensation medical certificate which stated that Mr Short was not able to work from 8 to 12 September 2012 apparently due to the exacerbation of chest wall pain. [42] Mr Short saw Dr Ng on Tuesday 11 September 2012. The x-ray showed no fractures and the lung was clear of infection. His medical history notes, however, that Mr Short said "pain the same." It also refers to "min back pain." Dr Ng gave evidence that at that stage there was "a bit of back pain but not much" and no tenderness over Mr Short's back. He continued to prescribe Tramal (a painkiller) mostly for the chest wall pain. The workers' compensation medical certificate issued by Dr Ng refers to chest wall pain and states that Mr Short was not able to work from 12 to 16 September 2012. The coughing incident of 12 September 2012 [43] During the night on Wednesday 12 September 2012, Mr Short was at his home. He gave the following evidence: "I woke up … and went to the kitchen to get a drink. At that time I had a very nasty cold and I was coughing a lot. When I was going back to bed I was - as I said, coughing, and I felt a very sharp pain and a crack - heard a cracking noise in my ribs, and I fell to the ground in extreme pain."3 [44] Mr Short gave evidence that the severe pain he experienced on that day was in his ribs. His partner, who was cohabiting with him at that time, also gave evidence that Mr Short was holding his chest as he lay in pain after falling. When making their final submissions, counsel for the parties agreed that the pain from that incident was rib pain rather than back pain. [45] Mr Short contacted the Wesfarmers claims management by telephone at 3:46 pm on 12 September 2012. He spoke to Ms Hart who recorded the following note of the conversation: "- W[orker] called to advise that he is in a lot of pain. Was up really early this morning/middle of the night as wasn't feeling well. Went to get a drink and was walking back to bed when i coughed. Felt a snapping noise and fell to the ground. Couldn't walk and partner had to help me get back to bed. - still in a lot of pain today. Have taken 4 tramal's today already just for the pain. Think i need to go to the hospital but the PA is so busy. Can i go to the mater private? - went to GP on thursday and had xray and was all clear. Just want to know what's going on. CO adv 3 Transcript of Proceedings, Coles Supermarkets Pty Ltd v Simon Blackwood (Workers' Compensation Regulator) (Queensland Industrial Relations Commission, WC/2013/313, Industrial Commissioner Neate, 18 March 2014) 23. -- 10 of 29 -- 11 - would need more information and can't confirm whether treatment at the private hospital can be approved as aggravation seems to have happened at home. - still awaiting IME report. - advised w to go back to GP" (Exhibit 3, errors in original) [46] On 12 September 2012, Mr Short also attended the MDC "for review" and saw another doctor. His medical history for that date includes the following notes: "still in pain+ left lowerr chest wall heard and felt a snap last night worse on turning or bending movements … pt well in pain+ … RS- left chest wall tenderness 8/9 ribs anteriorly … Not distressed … All options given/Pt not keen on any more XRS/Specialist referral given to pt/Red flags explained/To nearest hospital if any worse afterhours." [47] On Sunday 16 September 2012, Mr Short attended at the MDC in relation to a pain in his left side. His medical history notes "torn rib soft tissue". Dr Randall Jackson issued a workers' compensation medical certificate which stated that Mr Short was not capable for work from 16 to 19 September 2012. [48] Mr Short attended on Dr Ng on Wednesday 19 September 2012, and the entry in his medical history for that date states: "less L chest pain now minor R chest pain sl tender L chest wall return to work tomorrow 3 hr/day R/V Sun 23/9/12." There is no reference to Mr Short's back. Dr Ng issued a workers' compensation medical certificate which stated that Mr Short was suitable for restricted return to work from 20 to 23 September 2012. The certificate referred to "chest wall pain." [49] On Tuesday 25 September 2012, Dr Ng noted in the medical history "increases both lower lateral chest wall pain" (i.e. in his upper back) and "Lower back stiffness" after Mr Short had worked three hours on the previous Thursday and Friday. That work involved pushing a trolley. Dr Ng issued a workers' compensation medical certificate which stated that Mr Short was not able to work from 24 to 30 September 2012 due to his chest wall condition. [50] In his oral evidence, Dr Ng said that Mr Short had more pain and more stiffness on 25 September 2012 than when he first presented to Dr Ng in July. In his opinion, -- 11 of 29 -- 12 Mr Short continued with some back pain even at times when he said there was not much back pain and he was moving better. [51] The following day, Wednesday 26 September 2012, Mr Short attended at the MDC for physiotherapy and his medical history recorded that he complained of "lots of pain" on both sides of his ribs and the centre of his back. Mr Short could not lie flat or on his side, or do exercises, "due to pain+". He discussed a rehabilitation plan and was happy to try hydrotherapy the following Friday. [52] On Monday 1 October 2012, Dr Ng noted that Mr Short was "getting better" but was "still sore with movement" and apparently feared exacerbation if he returned to work earlier. Dr Ng issued a workers' compensation medical certificate which stated that Mr Short was not able to work from 1 to 7 October 2012. The certificate referred to "chest wall pain." [53] Mr Short commenced hydrotherapy on Friday 5 October 2012, and his medical history for Sunday 7 October 2012 notes that he "feels a lot better" and would like to try suitable duty for 4 hrs/day. His medication continued. He was issued a workers' compensation medical certificate which stated that Mr Short could return to work for suitable duties from 8 to 15 October 2012, and noted that his treatment included physiotherapy and hydrotherapy. First record of L5/S1 prolapse [54] On Tuesday 16 October 2012, Mr Short attended the MDC in relation to a recurrence of lower back pain. His medical history notes that Dr Goodman did not know the cause of the pain and ordered a CT of the lumbar spine. Dr Goodman issued a workers' compensation medical certificate which stated that Mr Short was not able to work from 16 to 23 October 2012. [55] On Monday 22 October 2012, Dr Ng noted that a CT of the lumbar spine on 19 October 2012 indicated "LS disc protrusion, compression on nerve root on R" and that lower back pain last week "radiated" to the posterior of his right thigh. This was worse after Mr Short had been sitting and in a car. He had been off work and was experiencing minor chest wall pain. He continued on hydrotherapy and experienced "mild pain lumbar rotation". Dr Ng issued a workers' compensation medical certificate which stated that Mr Short was not able to work from 22 to 28 October 2012. In his oral evidence, Dr Ng said that Mr Short's pain was worse in October than it had been in previous months, and Mr Short exhibited new symptoms of pain in the right thigh. [56] On Friday 26 October 2012, Kim Hart spoke to Mr Short by phone. He reported that he had a CT scan on his back as he was "getting more and more pain in the area." He said that he had a bulging disc which was pinching the nerve. He could not recall a specific incident that brought on the back pain, but reported a Sunday night a week or two ago when he started to feel pain in the buttocks then extended up to the spine. [57] On Sunday 28 October 2012, Mr Short attended the MDC. His medical history notes "back settling" and Mr Short would return to work for two hours daily, with a limit of 5 kg on the amount he should lift. Dr Randall Jackson issued a workers' -- 12 of 29 -- 13 compensation medical certificate which stated that Mr Short was able to perform suitable duties from 29 to 31 October 2012. This was the first such certificate to refer to the lumbar disc prolapse. [58] On Monday 29 October 2012, Mr Short attended the MDC. His medical history notes that the lower back pain was worse, that Mr Short did not start work that day but wants to try again on the Wednesday. Mr Short was "slow getting about" and exhibited "mild distress." Dr Ng issued a workers' compensation medical certificate which referred to the lumbar disc prolapse and stated that Mr Short was not capable of work between 29 and 31 October 2012. [59] On Friday 2 November 2012, Mr Short consulted Dr Ng. His medical history indicates that there was "no chest wall pain now", but his lower back pain was no better and had radiated to his post right thigh. He experienced some pain when leaning to the right and forward, and there was some restriction to his lumbar range of movement. He was continuing with physiotherapy. Dr Ng issued a workers' compensation medical certificate stating that Mr Short was not capable for any type of work from 1 to 11 November 2012 due to his lumbar disc condition. [60] On Sunday 11 November 2012, Mr Short consulted Dr Ng and reported that his right lower back pain was "worse," radiating to his right post thigh. The Tramal medication was inadequate, he did not attend physiotherapy because of the pain and was experiencing associated distress. Dr Ng increased the Tramal medication and referred Mr Short to Dr Ian Cheung, a spinal surgeon. Dr Ng issued a workers' compensation medical certificate stating that Mr Short was not capable for any type of work from 12 to 25 November 2012 due to his lumbar disc condition. [61] On Wednesday 14 November 2012, Mr Short attended the MDC. His medical history notes that he had experienced an aggravation of lower back pain and buttock pain in the last couple of weeks. There was no trigger that started it but he had significantly reduced range of movement in the lumbar spine. [62] In response to further instructions from Wesfarmers to provide an independent medical examination and report, Associate Professor Williams interviewed and examined Mr Short on Monday 19 November 2012. In a report dated 21 November 2012 ("the second report" (Exhibit 4)), he addressed issues that had arisen since the time of his first report dated 19 September 2012, specifically the “onset of sudden and severe right lower back pain and leg pain” approximately four weeks previously. He noted that, at the last review, Mr Short was working in a light duties capacity for six hours a day, five days a week, with a 5 kg lifting restriction and no bending. Mr Short remained on this program until the onset of symptoms in the right lower back and leg four weeks earlier. [63] Associate Professor Williams noted that a subsequent CT examination revealed a right L5/S1 disc prolapse causing right S1 nerve compression. Although the CT examination performed on 19 October 2012 had not been provided to him, his diagnosis was "Probable right L5/S1 disc protrusion with severe right S1 radicular pain." [64] The three aspects of the second report are particularly relevant to these proceedings. Associate Professor Williams: -- 13 of 29 -- 14 (a) described the seriousness of Mr Short's condition, noting that the symptoms are “constant and unremitting”, Mr Short is “unable to work at this time and is totally incapacitated due to the severity of his pain,” the condition “is not stable and stationary”, and there would not appear to be any likelihood of "spontaneous resolution"; (b) stated that Mr Short required review by a spinal surgeon and suggested that he would require some form of treatment to alleviate the right sided lower back and right leg pain (which may take the form of a discectomy if an MRI examination confirms the pathology); and (c) expressed the opinion that the "work related condition has resolved" and that the current symptoms were "unrelated to employment." [65] In relation to the third point, the second report states: "As far as I can gather, the symptoms arising at this time have no relationship to employment. They are unrelated to the circumstances of his fall of 28 June 2012 and these current symptoms were not present at my review on 19 September 2012. As commonly occurs, the symptoms have arisen spontaneously and are unrelated to any specific event." [66] Later, in response to specific questions from Wesfarmers, the second report states: "There is no injury. Specifically, symptoms are unrelated to the events of 28 June 2012. … Symptoms relate to a pre-existent L5/S1 discal prolapse which has become symptomatic. … Symptoms are unrelated to employment.” [67] WorkCover terminated Mr Short's claim for compensation and the benefits ceased from 23 November 2012. [68] Mr Short continued to receive treatment at the MDC, primarily from Dr Ng, in the following months. Dr Ng prescribed painkilling medication and issued some workers' compensation medical certificates. What the medical history and associated records from 30 June to 19 November 2013 indicate [69] There is no suggestion that Mr Short experienced any significant back pain or symptoms of any back injury or degenerative spinal condition before his fall on 28 June 2012. Mr Short attended the MDC frequently in the period between 30 June and late November 2012 (sometimes on consecutive days and rarely more than a week apart). He was examined by Associate Professor Williams on 20 August and 19 November 2012. -- 14 of 29 -- 15 [70] From the medical history notes prepared by general medical practitioners and a physiotherapist, and the reports of Associate Professor Williams, in that period it appears that: (a) Mr Short suffered a right transverse process fracture at L3 and the right 6th rib as a result of the fall, and he experienced various degrees of pain and discomfort in the following months. (b) Some of his movements were restricted and his ability to engage in some physical activities and to perform manual tasks was limited. (c) There were signs of improvement in his physical condition from mid- July 2012. That improvement is recorded in his medical history and is illustrated by the fact that he was certified to be able to return to work to perform light duties in reduced working hours from 16 July until 6 September 2012 (although there were a few days in late July and one day in August for which he obtained workers' compensation medical certificates stating that he was not able to work). (d) The focus of medical attention was on his lower back condition initially and until about the end of August 2012. (e) From 8 August until late September 2012 there were a fewer references to his back condition (which was said to be improving) and the focus was increasingly on his chest wall pain. (f) Stiffness and back pain became more noticeable from late September 2012 (along with ongoing chest wall pain) and became more pronounced in October 2012. (g) The chest pain ended by early November 2012. (h) The lumbar spine disc protrusion and compression on nerve root was identified on a CT of Mr Short's lumbar spine on 19 October 2012. (i) No symptoms of sciatica or other discomfort directly attributable to the L5/S1 disc prolapse were recorded until 22 October 2012, when Dr Ng noted that Mr Short reported that he experienced such symptoms in the previous week. Ms Short gave a similar account of when he experienced those symptoms to Ms Hart on 26 October 2012 and Associate Professor Williams on 14 November 2012. [71] Throughout the period when he was treating Mr Short, Dr Ng prescribed a range of medication including Tramal tablets and capsules, Panadeine Forte tablets, and Endone tablets (to relieve pain). The evidence of Mr Short and Mr McDonogh [72] Mr Short gave oral evidence about his symptoms in relation to his ribs and chest, lower back and right leg. He took issue with some of the evidence summarised above. -- 15 of 29 -- 16 [73] Ribs and chest: Mr Short said that the pain in his chest caused by the crates landing on his ribs took a little longer to be noticed than his lower back pain but there was "a slow, progressive healing process." By August 2012, his ribs were starting to feel slightly better, but the lower back pain was increasing. The pain in his ribs became worse at the time of the coughing incident on 12 September 2012. That event was related to his chest and not his back. His ribs started to heal after the coughing incident, but his back pain started to increase and became progressively worse, particularly on his right side. That prevented him doing housework and driving. [74] According to Mr Short, on 20 August 2012 when he first saw Associate Professor Williams, he was experiencing pain in his ribs and lower back. The ribs pain was the worst at that time. Mr Short recalled that Associate Professor Williams asked him to rate his pain on a scale of 1 to 10 (where 10 is the worst pain), and that he advised that the pain to his chest varied from 3/10 to 8/10 by that time. [75] Lower back: Mr Short could not recall telling Dr Ng on 13 July 2012 that he was getting better, or the range of movements of his lumbar spine that he demonstrated at that time. Indeed he asserted that the pain in his lower back was not getting better at that time and that he did not tell Dr Ng that it was getting better. He said that his back did not improve over the course of physiotherapy. Around July 2012 "it was stable, but it wasn't improving at all." Mr Short said that the pain was not improving in August 2012, and he did not remember telling Dr Ng that his lower back was feeling much better. [76] Mr Short recalled advising Associate Professor Williams of the levels of pain he was experiencing, and of his lack of sleep because his lower back was sore. However, Mr Short denied telling Associate Professor Williams on that occasion that his lower back pain was about 1/10 or 2/10 or that it was all but resolved. At the hearing he stated that his lower back pain in August 2012 was "significant" and he suggested that it was "possibly" a 4/10 or 5/10. He also denied having the range of movement (e.g. being able to reach above his ankle) recorded on that occasion. [77] Mr Short said his back was stiff and painful in the weeks after that consultation, but he did not recall seeing other doctors in those weeks or what he said to them. Consequently he could not explain why the notes of those consultations in his medical history conflict with his evidence about his level of back pain. [78] Right leg: Mr Short said that he started experiencing a shooting pain in his right leg around September 2012. It commenced as a mild pain and progressively increased in intensity until it was at its worst in October 2012. Mr Short: (a) could not explain why, when he saw Dr Ng on 22 October 2012, he said that he had experienced the problem for one week; (b) suggested that Associate Professor Williams was wrong when he recorded that Mr Short reported the onset of sudden and severe right lower back and leg pain approximately four weeks before 19 November 2012; and -- 16 of 29 -- 17 (c) did not recall telling Associate Professor Outerbridge that he noticed a gradual onset of a shooting pain down the front of his right thigh approximately two weeks after the accident, but said "I might have got it wrong … in regards to the timing of the event." [79] For completeness, I note that evidence was given by Mr Short's partner, Liam McDonogh, to the effect that: (a) from the time of his accident in June 2012, Mr Short found it difficult to sleep as it was painful to lie on his back or his side; (b) by about August 2012, Mr Short appeared to be in quite a lot of pain in his rib and back area, was limited in his movements, and needed assistance with some day-to-day tasks; (c) following the coughing incident on 12 September 2012, Mr Short was unable to do basic chores and required assistance at home with cleaning, cooking and dressing; (d) there was a gradual onset of worsening back pain and Mr McDonogh took time off work to help Mr Short; (e) from about September 2012, as his pain got worse, Mr Short would favour his right leg and foot by raising the foot off the ground to take pressure off it. Mr Short's second compensation claim [80] On 19 April 2013, Mr Short completed an Employee's Application for Compensation in relation to the injury on 28 June 2012. He described the location of the injury as "Lower back" and the nature of the injury as "L5/S1 disc protrusion". He described the circumstances in which he sustained his injury as follows: "I was carrying crates of groceries to the customers rear entrance. As I was walking down wet concrete steps, I slipped and landed on the edge of one of the steps and the crates landed heavily on my chest and ribs." [81] The acceptance of that claim by the Respondent is the subject of the appeal in these proceedings. As will be apparent, the events which gave rise to Mr Short's first (and initially successful) compensation application and the circumstance in which the payment of compensation ceased provide the background to the present proceedings and the context for determining the appeal. Expert medical opinion evidence [82] Medical evidence was given by: (a) Dr Ng, Mr Short's general medical practitioner; -- 17 of 29 -- 18 (b) Associate Professor Outerbridge, an orthopaedic surgeon who performed spinal surgery in the early years of his career and continues to see patients with spine complaints and assists a spinal surgeon on a regular basis; and (c) Associate Professor Williams, an orthopaedic spinal surgeon who is the head of the Orthopaedic Spinal Surgical Services at the PA Hospital dealing with trauma and spinal cord injury. [83] Most of the evidence given by Dr Ng has already been considered in the course of noting the sequence of consultations involving Mr Short. Dr Ng also provided a broad overview of Mr Short's progress. He recalled treating Mr Short for back pain and chest wall pain and described the level of back pain experienced by Mr Short between July and October 2012 as "mild." Although Mr Short appeared to be somewhat better by 22 July 2012, Dr Ng could not recall a time between July and October 2012 when Mr Short was free of pain; he always had "some sort of mild back pain". Around October 2012, Mr Short seemed to have worsened progressively so that he could hardly move. He had very restricted movement in sections of his body. [84] In one important respect, the two specialists were in agreement. Associate Professor Outerbridge said that a fracture of the transverse process of L3 would take a minimum of three months to heal but could take longer. Consequently, a patient would experience pain in their lower back for three to four months. If the fracture was virtually undisplaced (as appears to have been the case with Mr Short) the symptoms would be much less than for a displaced fracture, so the period could be shorter. [85] Associate Professor Williams said he would expect that type of injury would become pain-free in up to three months. By 20 August 2012, Mr Short was not symptom-free but was proceeding towards resolution along the same time line which is common for these injuries. [86] However, the specialists disagreed in relation to the central issue in this case, namely whether the L5/S1 disc prolapse was caused by Mr Short's fall on 28 June 2012 and hence was a work-related injury. The opinion of Associate Professor Outerbridge [87] Expert evidence was given by Associate Professor Outerbridge in a detailed written report dated 9 December 2013 (Exhibit 8) and oral evidence. He gave oral evidence in relation to: (a) the mechanism for the fracture of the right transverse process of L3; (b) when the disc prolapse might have occurred; and (c) the mechanism by which the disc prolapse might have occurred and hence whether it was work related. -- 18 of 29 -- 19 [88] Associate Professor Outerbridge interviewed and examined Mr Short on 26 November 2013, and reviewed available records and files data (including, the first and second reports of Associate Professor Williams and a report by Dr Cheung but not the general practitioners' notes for the first few months after Mr Short's fall in June 2012). In his report, Associate Professor Outerbridge described the nature of the injury as "Fracture transverse process at L3 and 6th rib and L5/S1 disc prolapse." He noted that, unless otherwise specified, the information in his report was obtained from his interview with Mr Short. Consequently, the only information he had in respect to the timing of symptoms was what Mr Short told him and what was in Associate Professor Williams' examination. Having subsequently considered the general practitioners' notes, he agreed that in July and August 2012, Mr Short was reporting improvements in his back pain consistently with the fracture injury that he suffered. Mr Short then reported that his symptoms were getting worse in the weeks leading up to the sciatica in October. That material, which indicated some inconsistencies with what Mr Short had told him, did not alter his opinion about whether the disc prolapse was a work-related injury. [89] Mechanisms for fracture: Associate Professor Outerbridge described two mechanisms that might cause a fracture of the right transverse process of L3: (a) most commonly, a sudden contraction of the muscles that are attached to the tip of the transverse process; and (b) a blunt instrument hitting the transverse process. He speculated that Mr Short’s injury was probably the result of a muscular contraction as a result of his fall. [90] He stated that it is difficult to isolate the symptoms that arise directly as a result of such a fracture because the muscles on the left and right sides of the spine are usually contused. So the person experiences both the spasm of the muscles around the lower back and the fracture. A combination of pain arising from the fracture and from the contused and bruised muscles in the vicinity of the fracture would be experienced as a general ache, which varies in intensity with such things as movement and occasional muscle spasms. Pain might also be increased by rolling over in bed or lifting a box. [91] When disc prolapse occurred: Having conducted a physical examination of Mr Short on 26 November 2013, Associate Professor Outerbridge wrote: "In the lumbar area he had tenderness over the spinous processes of L3, L4, L5 and S1. He also had an area of tenderness in the region of the paraspinal muscles on the right side of the lower lumbar spine. This tenderness extended out to the flank." [92] He also noted that the point at which Mr Short stated to experience clear symptoms of a disc prolapse with lower extremity complaints was "unclear." [93] Associate Professor Outerbridge thought that the disc prolapse occurred when the sciatica symptoms became apparent which, on Dr Ng’s records, was some time in October 2012. -- 19 of 29 -- 20 [94] Mechanism for disc prolapse: Associate Professor Outerbridge expressed his opinion that: “on the balance of probabilities, [Mr Short] probably sustained an injury to the annulus of the disc, which ... didn’t lead to an immediate prolapse, but ultimately led to the disc prolapsing.”4 [95] Associate Professor Outerbridge explained his opinion that Mr Short’s fall was a significant contributing factor to the disc prolapse. In essence, the process of degeneration that leads to a prolapse occurs over a long period but the rupture can be caused by a fairly minor episode. He use the analogy of a tyre on a car which becomes worn over a long period (e.g. with fibres in the wall of the tyre having been torn when the tyre hit a kerb) and has a blowout. In Mr Short’s case, the degree of trauma associated with the transverse process fracture and a fractured rib suggests that there was a significant degree of trauma to the lower back. [96] Associate Professor Outerbridge did not contend that Mr Short had a significant traumatic event in the immediate history leading to his disc prolapse, but his "feeling is" that the fall some months earlier "considerably contributed to the … demise of his disc." He agreed that a disc prolapse can occur in response to a reasonably innocuous event such as bending over to pick up something or possibly a cough or sneeze. [97] In making his diagnosis, he paid careful regard to the notes of the medical practitioners (which first refer to lower extremity pain in October 2012) rather than Mr Short's description of when he first experienced pain in his right leg and the location of that pain. Associate Professor Outerbridge referred to Associate Professor Williams' first report in relation to Mr Short's capacity for straight leg raise and the fact that there was no evidence of root tension signs at the time of that preliminary examination. That would not be consistent with a prolapse at the time of that examination. [98] When considering what symptoms earlier than October 2012 might have indicated that Mr Short had a disc prolapse, Associate Professor Outerbridge gave evidence that it would be very difficult to isolate any pain arising from the disc area from back pain that Mr Short experienced from such things as his fractured transverse process at L3 and associated muscular conclusion. He said that there is controversy among spinal surgeons as to how much pain an isolated annular tear can cause. That depends on how extensive the tear is. Annular tears are not necessarily very symptomatic, and a person can have a weakness there which can be asymptomatic. [99] In that context he expressed the view that, although Dr Williams did not find anything in relationship to a disc prolapse or sciatica, that does not necessarily mean the disc prolapse was not connected to Mr Short's fall. Rather, Mr Short had "quite a significant fall" which caused enough contusion, enough muscle contraction, to cause a transverse fracture rupture as well as fractured ribs. The significant fall was on top of a degenerative L5/S1 disc and "the balance of probabilities probably led to 4 Transcript of Proceedings, Coles Supermarkets Pty Ltd v Simon Blackwood (Workers' Compensation Regulator) (Queensland Industrial Relations Commission, WC/2013/313, Industrial Commissioner Neate, 18 March 2014) 59. -- 20 of 29 -- 21 him having weakness in his annulus, and ultimately contributed a great deal to him having his prolapse." Although Associate Professor Outerbridge seemed to accept that Mr Short's lower back pain had almost completely resolved within about two months after his fall, he thought that the fall contributed to "an injury to the disc, and predisposed him [to] rupturing later on." [100] In relation to the range of physical injuries sustained by Mr Short on 28 June 2012, Associate Professor Outerbridge wrote that, at the date of his report (some 18 months later): (a) the physical injuries include fractured ribs, right fractured transverse process L3 and aggravation of pre-existing degenerative changes at lower back; (b) he could not find "any significant inconsistencies between the injury and the described mechanism of alleged injury"; (c) Mr Short's chest examination was completely normal and this condition had "resolved completely"; (d) there is no doubt Mr Short had evidence of pre-existing degenerative change, however, the ongoing symptoms relate to the aggravation of the pre-existing condition; (e) this is a work-related injury; (f) the work-related aggravation of his pre-existing condition had not ceased; (g) there was ongoing incapacity and this incapacity was partial; (h) the work-related injury was not stable and stationary, and it would be at least six months before it became so. [101] Associate Professor Outerbridge agreed that his diagnosis of Mr Short's condition was retrospective, that is, he was working backwards in time to ascertain whether there was any causal relationship between the prolapse in about October 2012 and Mr Short's fall on 28 June 2012. The opinion of Associate Professor Williams [102] Associate Professor Williams also gave evidence in relation to: (a) the mechanism for the fracture of the right transverse process of L3; (b) when the disc prolapse might have occurred; and (c) the mechanism by which the disc prolapse might have occurred and hence whether it was work-related. -- 21 of 29 -- 22 [103] Mechanism for fracture: Associate Professor Williams described the two mechanisms for causing fractures of the transverse processes of the lumbar spine as: (a) most commonly, a direct blow to the spine (e.g., falling onto an object or being kneed in the back); and (b) a fracture of the transverse processes in conjunction with another injury (e.g., injury to the pelvis). [104] In his opinion, it is likely that the fracture to Mr Short's transverse process at L3 was the result of a direct trauma rather than a muscle spasm. He disagreed with the opinion expressed by Associate Professor Outerbridge because evulsion is most commonly associated with multiple fractures of transverse processes as the muscular attachments are to all five lumbar transverse processes. An isolated L3 fracture would not be consistent with muscular evulsion. [105] When disc prolapse occurred: Associate Professor Williams was unable to say when the disc prolapse occurred. When he first saw Mr Short on 20 August 2012 there were no symptoms to suggest an acute discal injury. [106] Mechanism for disc prolapse: Associate Professor Williams described the degenerative condition as progressing along a continuum rather than as an episodic event, although symptoms can flare up or settle from time to time. A disc prolapse is one possible outcome in the natural history of a degenerative disc. It does not occur as a result of trauma. [107] There is no certainty about when leg pain is related to a discal prolapse, that is, at what point the disc material that is responsible for the pain is emitted from the disc. For a large number of patients, the pain is described in the leg after a discal prolapse has occurred. There are two common mechanisms by which leg pain starts: (a) a pre-existent discal prolapse; and (b) a discal extrusion when the disc material comes to sit up against the nerve and irritates it. Associate Professor Williams was not aware of any relationship between episodes of lumbar spinal pain and the onset of subsequent leg pain in relation to a discal prolapse. [108] As I understand his oral evidence, Associate Professor Williams disagrees with Associate Professor Outerbridge because, in summary: (a) the injury causes immediate or very soon following symptoms after the initial traumatic event and those symptoms generally improve over a period of time, sometimes to complete resolution and sometimes not; (b) the mechanism of injury is inconsistent with discal injury, in particular because: -- 22 of 29 -- 23 i. a fracture of the transverse process of the L3 vertebrae is generally caused by a direct blow or fall directly on to the spine which is not a consistent mechanism for an injury sustained by an inter- vertebral disc, because there is no well-established mechanism by which discal injuries occur in response to trauma (other than in the most extreme examples); and ii. inter-vertebral disc damage or the perpetuation or exacerbation of a degenerative process is generally a result of either repetitive axial loading (whereby there is a consistently increasing weight imposed upon the lumbar spine) or increased intra-abdominal pressure (such as observed in coughing, sneezing and similar activities). Mr Short's fall was not consistent with either of those types of force being applied to the spine; (c) at the time of his review in August 2012, Mr Short had no symptoms of spinal injury, including lumbar spinal pain, nor leg pain which could be said to be the result of a discal prolapse at L5/S1 (and if he had suffered a form of discal injury that would have been obvious to Associate Professor Williams at the time of his review, or would have been evident on the bone scan of Mr Short). He expanded on these options in the course of cross-examination. [109] Although it was not possible to describe the state of Mr Short's lumbar spinal discs at the time he first saw Mr Short, Associate Professor Williams did not think the prolapse could have occurred on the day of the fall because that was not a mechanism that causes discal prolapse. He acknowledged that there is some interest amongst orthopaedic surgeons about the process of disc degeneration and that various theories have been advanced about the cause of such degeneration and the mechanism of discal prolapse. Although it has been hypothesised that mechanical forces (such as vibration, torsion and compression) contribute to disc degeneration, Associate Professor Williams did not consider that such forces could cause discal degeneration. He is more open to the concept that those mechanisms would be more likely to cause exacerbation or worsening of a pre-existing degenerative process. That is, those mechanisms would not have any effect on the process of degeneration but could make a degenerative process painful. [110] Associate Professor Williams agreed that Mr Short would have experienced considerable and continuous muscle spasm in his lumbar back region in the period following his fall, but did not consider that such forces were compressive or torsional at the time of the fall. [111] Although the L3 transverse process fracture was consistent with the mechanism of Mr Short's fall, there were none of the usual mechanisms commonly associated with exacerbation of pre-existing degeneration in the spine (e.g., axial loading, intra- abdominal pressure). The pain which Mr Short described as occurring immediately after the incident and up until 20 August 2012, was consistent with the fracture he had sustained and the associated soft tissue injury but, in Associate Professor -- 23 of 29 -- 24 Williams' view, was not consistent with aggravated lower back pain from degenerative processes or leg pain from neuralgic compression. [112] At 20 August 2012, Mr Short did not have any signs or symptoms to suggest that a degenerative process at L5/S1 had been aggravated or speeded up because of his fall, nor did he have any clinical signs consistent with an aggravation of degeneration at L5/S1 that later lead to a prolapse. Although he may have complained of pain further into the lower back then, the area which he described which was more typical of L3 and consistent with his injury, Mr Short had no signs or symptoms radiating to the buttock or leg consistent with neuralgic compression. [113] As noted earlier, in his second report dated 21 November 2013, Associate Professor Williams expressed the view that Mr Short's work-related condition had resolved and his symptoms at that time related to a pre-existent L5/S1 discal prolapse, which had become symptomatic. Those symptoms were unrelated to Mr Short's employment and in particular to the events of 28 June 2012. [114] Associate Professor Williams confirmed that opinion in a supplementary report dated 30 October 2013 ("the third report" (Exhibit 6)) which he prepared after examining a report prepared by Dr Ian Cheung. Dr Cheung's report was not in evidence and he did not give oral evidence in these proceedings. In the third report, Associate Professor Williams wrote: "I am unable to agree that symptoms arising in the lower back and right leg have any relationship to the claimant's fall occurring in June 2012. My reasoning is that I reviewed the claimant for the purposes of an IME on 19 September 2012 and the claimant had no symptoms in the lumbar spine or the right leg. Symptoms therefore commenced following my review of 19 September 2012 and cannot, therefore, feasibly be attributed to the events of 28 June 2012. Although the claimants may well require surgical intervention to treat his condition, in my opinion this treatment would not be considered compensable under the Act." The approach to assessing the conflicting evidence [115] In order to assess the, at times, conflicting evidence in these proceedings it is appropriate to outline a general approach and guiding principles. [116] First, there are inconsistencies between the medical (and some other) records summarised earlier and Mr Short's recollection of the progress and course of his lower back pain. The Respondent submits that the unreliability of Mr Short's memory of times and dates would not be unusual in the experience of a layperson, particularly one who has suffered a traumatic experience and pain and has been taking of strong analgesics and where the events occurred some 18 months before they gave evidence. I agree, but that lends support to the view that where there is a clear conflict between Mr Short's recollections and the contemporaneous records of disinterested medical practitioners, the latter should be preferred. [117] I will take that approach, particularly because Mr Short attended on doctors and a physiotherapist quite frequently between 30 June 2012 and late November 2012, sometimes on successive days and rarely more than a week apart. The medical -- 24 of 29 -- 25 history notes and medical reports rely to a significant extent on what Mr Short said to those who were treating him. I accept them as accurate records of what the medical professionals were told and observed. [118] That is not to conclude that Mr Short intended to be misleading in his evidence. In some respects, as Associate Professor Outerbridge suggested, he might have been confused. However, Mr Short's evidence was a recollection or reconstruction of events or his experience of levels of pain a significant time before the hearing and was not necessarily reliable in every detail. The same observation is made in respect of some of the oral evidence given by Mr McDonogh to the extent that it is inconsistent with contemporaneous documentary records. [119] Second, as the Respondent submits, the medical evidence can assist the Commission but cannot determine the issue whether Mr Short's injury arose out of or in the course of his employment. It is the role of a court or this Commission to determine questions of fact in the face of medical testimony.5 [120] It should also be noted that where, as in this case, there is a conflict of opinions between expert medical witnesses the following propositions drawn from judicial authorities apply: (a) the tribunal of fact can be assisted by expert medical opinion evidence, but must weigh and determine the probabilities as to the cause of an ailment or injury having regard to the whole of the evidence;6 (b) the tribunal's duty is to find ultimate facts and, so far as it is reasonably possible to do so, to look not merely at the expertise of the expert witness, but to examine the substance of the opinion expressed and (where experts differ) to apply logic and common sense to the best of its ability in deciding which view is to be preferred or which parts of the evidence are to be accepted;7 (c) only when medical science denies that there is a connection between, for example, certain events and a person's death can a judge not act as if there were a connection; but if medical science is prepared to say that it is a possible view, then the judge after examining the lay evidence can decide that it is probable;8 (d) the finding could be described as one based on the credibility of expert witnesses, having regard to such things as whether the witnesses display signs of partisanship in the witness box or lack of objectivity, and 5 See Gaudry v Pacific Coal P/L [1996[ QCA 525; Adelaide Stevedoring Company Ltd v Forst (1940) 64 CLR 538, 563 (Rich ACJ). 6 Ramsay v Watson (1961) 108 CLR 642, 645 (Dixon CJ, McTiernan, Kitto, Taylor and Windeyer JJ); see also Adelaide Stevedoring Company Ltd v Forst (1940) 64 CLR 538, 563-4 (Rich ACJ); Chattin v WorkCover Queensland (1999) 161 QGIG 531, 532-3 (Williams P), quoting Obstoj v Van de Loos (Unreported, Supreme Court of Queensland, Connolly J, 16 April 1987). 7 Holtman v Sampson [1985] 2 Qd R 472, 474 (DM Campbell, Macrossan and Thomas JJ). 8 Commissioner of Police v David Rea [2008] NSWCA 199, [8] (Handley AJA, with whom Allsop P and Johnson J agreed), quoting EMI (Australia) Limited v Bes (1970) 44 WCR 114, 119 (Herron CJ); see also Chattin v WorkCover Queensland (1999) 161 QGIG 531, 532 (Williams P), quoting Fernandez v Tubemakers of Australia Ltd [1975] 2 NSWLR 190, 199-200 (Mahoney JA). -- 25 of 29 -- 26 whether they make proper concessions to the viewpoint of the other side;9 (e) distinctions may be drawn on the basis of demeanour (a limited ground where experts are under consideration); qualifications, impressiveness and cogency of reasoning and exposition of reasoning; preparation for, and application to, the problem in hand; and the extent to which the witness had a correct grasp of basic, objective facts relevant to the problem;10 and (f) if it is open to the tribunal to prefer one body of evidence to the other on grounds fairly discerned, the tribunal should express its reasoned preference.11 [121] In applying those propositions in the present case, it is also necessary to remember that these proceedings are conducted as a hearing de novo and the Appellant bears the onus of proof on the balance of probabilities.12 Submissions [122] The Appellant submits that, having regard to the inconsistencies between the evidence of Mr Short and the contemporaneous medical records, a more reliable indication of the progression of symptoms over time is found in those records. As noted earlier, I have proceeded on that basis. The Appellant then relies on the expert evidence of Associate Professor Williams that Mr Short's fall on 28 June 2012 did not contribute to the L5/S1 disc prolapse identified in October 2012. In summary, Associate Professor Williams formed that view because: (a) his examination of Mr Short on 20 August 2012 elicited no signs of damage to the annulus of the disc at L5/S1 and (had the annulus been damaged at that time) he would have expected such signs or symptoms to be present; (b) the mechanism of the fall was a "classic" mechanism of injury for an L3 transverse process fracture, but not an acknowledged mechanism for an L5/S1 disc injury; (c) there was no trauma in the structures surrounding the L5/S1 disc which would be expected if the disc had been damaged at the time of the fall. That trauma would have been revealed in the bone scan that demonstrated the rib fracture and L3 transverse process fracture. 9 Holtman v Sampson [1985] 2 Qd R 472, 474 (DM Campbell, Macrossan and Thomas JJ), quoting Joyce v Yeomans [1981] 1 WLR 549, [1981] 2 All ER 21, 27, (Brandon LJ). 10 Monroe Australia Pty Ltd v Campbell (1995) 65 SASR 16, 27 (Bollen J), quoting Sotiroulis v Kosac (1978) 80 LSJS 112 (Wells J). 11 Monroe Australia Pty Ltd v Campbell (1995) 65 SASR 16, 27 (Bollen J), quoting Sotiroulis v Kosac (1978) 80 LSJS 112 (Wells J). 12 Rossmuller v Q-COMP (C/2009/36) - decision http://www.qirc.qld.gov.au, [2]; State of Queensland (Queensland Health) v QComp and Beverley Coyne (2003) 172 QGIG 1447; Qantas Airways Limited v QComp (2006) 181 QGIG 301. -- 26 of 29 -- 27 [123] The Appellant submits that the Commission should prefer the opinion of Associate Professor Williams to that of Associate Professor Outerbridge for the following reasons: (a) Associate Professor Williams is a specialist spinal surgeon with directly relevant experience in the area of spinal trauma, whereas Associate Professor Outerbridge has less recent experience of performing spinal surgery; (b) Associate Professor Williams had the advantage of seeing Mr Short on 20 August 2012, a date directly relevant to the period of time within which this appeal is concerned; (c) Associate Professor Outerbridge examined Mr Short in November 2013 (about 18 months after Mr Short's fall and more than a year after the L5/S1 disc prolapse was identified), and was making a "retrospective diagnosis" of the likely cause of the disc prolapse; (d) although Associate Professor Outerbridge accepted that disc protrusions occur without significant trauma particularly in degenerative discs (which Mr Short's L5/S1 disc was shown to be), he expressed the opinion that a fall which was sufficiently significant to cause an L3 transverse process fracture probably contributed to a subsequent disc protrusion; (e) Associate Professor Outerbridge accepted that, for his opinion to be correct, the damage to the annulus must have caused no significant symptoms to Mr Short by 20 August 2012 (even though he said only some annular tears cause no symptoms), whereas Associate Professor Williams said that if an annular tear had been suffered the symptoms would have been present and discernible by him on 20 August 2012; (f) it is counter-intuitive to suggest that Mr Short's disc might have been damaged in the fall, had healed with rest and medication so as to be asymptomatic by 20 August 2012, but then played a relevant part in the subsequent disc prolapse; (g) Associate Professor Outerbridge had regard to the opinion of another specialist spinal surgeon, Dr Ian Cheung, whose opinions were not before the Commission; (h) when forming the opinion expressed in his report, Associate Professor Outerbridge did not have the relevant sections of the general practitioners' notes which indicated that Mr Short's symptoms improved during July and August 2012; (i) Associate Professor Outerbridge thought the L3 transverse process fracture was caused by muscle spasm, but Associate Professor Williams gave a convincing explanation as to why that was implausible and said that the L3 transverse process fracture was more likely to have been -- 27 of 29 -- 28 caused by blunt trauma, a conclusion supported by the general practitioner's account of marked bruising; and (j) Associate Professor Williams was alert to the prospect of an undiagnosed injury and ordered a bone scan which discerned the presence of the right 6th rib and L3 transverse process fracture. [124] The Respondent relies on the opinion of Associate Professor Outerbridge that the fall on 28 June 2012 did not lead to an immediate disc prolapse of Mr Short's L5/S1 disc but probably significantly contributed to the eventual disc prolapse which occurred most likely two or three months after the injury, about the time of the reporting of sciatic symptoms. Although doubt was cast on some of the information provided to him by Mr Short, those discrepancies were not relevant to the expert opinion of Associate Professor Outerbridge. [125] The Respondent submits that the Commission should not accept Associate Professor Williams' view that the mechanics of the fall and the subsequent muscle spasm was not consistent with either torsional or compression forces. In its submission, that view was dogmatic and was expressed even though the expert was not present at the fall or in a position to have assessed the degree of torsional or compression forces. Associate Professor Williams agreed that the pathogenesis of the disc degeneration and disc prolapse was the subject of various theories, but agreed that ageing, genetic, mechanical and structural factors played a part. He could not determine when Mr Short's disc prolapse had occurred and conceded that the precise process by which it had occurred was unknown and subject to varying views. However, he would not accept that a disc prolapse had been associated with an earlier injury associated with the fall on 28 June 2012, in essence because in his view the mechanism of the fall could not cause a disc injury of this type. [126] The Respondent submits that the entirety of the factual and medical evidence does not lead to a conclusion that, on the balance of probabilities, Mr Short's disc prolapse did not arise out of the fall which occurred in the course of his employment or that the fall was not a significant contributing factor. Consequently, the appeal should fail. Consideration and conclusion [127] Without again traversing all the evidence and submissions, I note that, having considered the respective qualifications and experience of the two orthopaedic surgeons and particularly the timing and extent of their respective examinations of Mr Short, I am persuaded by his reasoning and observations to accept the opinions of Associate Professor Williams in relation to the physical consequences for Mr Short of the fall on 28 June 2012, the mechanism for the fractures resulting from that fall, and the apparently unrelated prolapse of a degenerative disc at L5/S1 some two to three months later. [128] Having regard to the evidence as a whole, particularly: (a) the medical and other records which provide an account of Mr Short's progress after the fall on 28 June 2012, including when the L5/S1 -- 28 of 29 -- 29 condition was identified and the absence of symptoms or other evidence of it previously; and (b) the opinion evidence from orthopaedic surgeons and the examinations and material on which they relied, I conclude that the L5/S1 disc prolapse suffered by Mr Short did not arise out of, or in the course of, Mr Short's employment and hence that employment was not a significant contributing factor to the injury. [129] The appeal is allowed. The decision of the Regulator dated 30 August 2013 is set aside. The Respondent is to pay the Appellant's costs of an incidental to the appeal. [130] Order accordingly. -- 29 of 29 --