appellant. The tribunal set aside the decision under review and, in place of that decision, decided that Comcare is liable to pay compensation under the Safety, Rehabilitation and Compensation Act 1988 for...
Key principles
The tribunal accepted the applicant's lay evidence and preferred the expert opinion of Mr Paul Carney over Dr Stevenson, finding that on the balance of probabilities the...
Concurrent radiological evidence indicating a large left-sided L5/S1 prolapse on the 8 August 2002 CT, together with degenerative change on the 22 March 2002 CT and the history...
In resolving conflicting medical opinion, the tribunal must apply common sense to the whole of the evidence, including lay testimony and documentary material, rather than relying...
Issues before the court
Whether the applicant's incapacity for work and medical expenses claimed in 2006 are caused by the injury suffered on 24 December 1990.
Cited legislation
1 cited instrument linked from this judgment.
Plain English Summary
The Tribunal found that the applicant's ongoing back problems and medical costs in 2006 were caused by the workplace back injury he suffered on 24 December 1990. It preferred the treating expert who linked the 1990 incident to later disc pathology and accepted the applicant's consistent account of ongoing symptoms, setting aside Comcare's refusal and ordering compensation.
AI-generated legal information, not legal advice. Zoe can make mistakes. Check the cited source, and for advice about your situation consult a qualified Australian lawyer.
Deep Dive
1,608 words · generated 05/07/2026
What happened
Neang Yun, a former registered nurse employed at the Royal Canberra Hospital, injured his lower back on 24 December 1990 while lifting and turning a heavy disabled patient with two other nurses. He experienced an immediate sharp lower back pain with radiation into the left leg, collapsed and required hospital treatment, including an overnight stay and an injection for pain [7]. Comcare accepted liability in 1991 for an acute lumbosacral muscle and ligament strain. The applicant continued working, experienced ongoing low back pain and took analgesics for years, and moved interstate in the 1990s. In 2001–2002 he sought renewed medical attention; CT scanning in March 2002 showed degenerative change at L5/S1 and a later CT in August 2002 showed a large left-sided L5/S1 disc prolapse [22–23]. In March 2006 the applicant claimed ongoing compensation for incapacity and medical expenses allegedly attributable to the 1990 injury; Comcare rejected the claim and that decision on reconsideration was the subject of tribunal review [2]. The Administrative Appeals Tribunal, Deputy President D G Jarvis, heard evidence (including competing expert opinions from neurosurgeon Mr Paul Carney and physician Dr Peter Stevenson, GP evidence, radiology and the applicant’s own testimony) and set aside Comcare’s decision, finding the 2006 incapacity and medical expenses resulted from the 1990 workplace injury and ordering Comcare liable for compensation [25, 28–29].
Why the court decided this way
Three strands of reasoning drove the tribunal’s conclusion.
Credibility and weight of lay evidence. The tribunal accepted the applicant as a credible and frank witness, and gave weight to his consistent history of ongoing low back and left leg symptoms, and to his explanation for not seeking continuous medical treatment while remaining employed at the hospital (cultural reticence, fear of job loss and the comparative triviality of the symptoms against his earlier life experiences) [4, 12–13, 25]. That factual narrative was crucial because causation is assessed by reference to the whole of the evidence, not merely statistics.
Preference between competing experts. The tribunal confronted directly differing medical opinions. Both specialists agreed that a plain x-ray at the time of injury would not rule in or out a disc prolapse, that the March 2002 CT showed degenerative change at L5/S1, and that the August 2002 CT showed a large left-sided L5/S1 prolapse [21–23]. Mr Carney gave a causal explanation linking the 1990 incident to an annular tear and a vulnerable disc subject to recurrent flare-ups and later scarring and nerve root compression; he relied on a history of immediate severe pain with sciatica, confinement to bed and a protracted recovery followed by intermittent symptoms [23]. Dr Stevenson posited a natural progression of non-specific degeneration, relying in part on the absence of medical consultations between the early 1990s and 2001 [25]. The tribunal preferred Mr Carney’s view, principally because it accepted the applicant’s account of persistent symptoms and analgesic use over the years, and found Carney’s explanation consistent with the radiological and clinical picture [25].
Method of reasoning on causation. The tribunal applied the common-sense approach to causation endorsed in March v E & M H Stramare, considering all evidence rather than treating group statistics as determinative. It recognised that statistical surveys may inform general likelihoods but cannot substitute for an individualised determination of causation based on the totality of evidence [26, 28]. The tribunal therefore integrated the clinical findings, the experts’ concurrent admissions about the CT evidence, the applicant’s credible history and the medical explanation that an annular tear can leave a disc vulnerable to recurrent problems, and found the link on the balance of probabilities.
Before and after state of the law
Before this decision there was already established guidance in administrative and civil causation: an assessment by reference to the balance of probabilities and a commonsense evaluation of all evidence, including the respective weight of medical opinion and lay testimony (Stramare). This decision follows those contours and applies them in the statutory compensation setting.
The decision reinforces two practical points for practitioners and decision makers:
Expert disagreement must be resolved by careful appraisal of the factual matrix and the credibility of lay witnesses; an expert opinion that aligns with a credible factual narrative and the contemporaneous documentary record will often be preferred (paras 21–25).
Epidemiological or statistical studies, while relevant, have limited force when adjudicating causation for a specific individual (para 26). The tribunal explicitly cites and relies on Laube for that caution.
Thus the decision does not change the law but exemplifies proper application of existing doctrines to a worker’s compensation claim involving delayed radiological confirmation and competing medical views.
Key passages with plain-English translation
"They gave helpful concurrent evidence as to the significance of the available radiological evidence..." [21]
Translation: The two medical specialists agreed on what the scans showed; that common ground made their differences clearer and easier for the tribunal to resolve.
"The fact that the x-ray report was normal was of no significance to the issue..." [21]
Translation: A normal x-ray at the time of injury does not prove there was no disc prolapse because plain x-rays do not detect disc herniations.
"I prefer Mr Carney's conclusion ... namely that Mr Yun's recent pain and disability is due to the natural progression of non-specific degeneration..." [25]
Translation: The tribunal decided Mr Carney’s diagnosis (that the 1990 injury caused a vulnerable disc leading to later problems) was more persuasive than Dr Stevenson’s view that the condition was merely degenerative ageing.
"Statistical evidence does not necessarily apply to any particular individual..." [26]
Translation: Studies about groups cannot override the specific facts of an individual’s case.
"I am satisfied that the incapacity and medical expenses ... have resulted from the injury that Mr Yun sustained..." [28]
Translation: On balance of probabilities, the tribunal found the applicant’s current problems were caused by the 1990 workplace injury.
What fact patterns trigger this precedent
This decision is relevant where:
There is an initial workplace incident producing acute symptoms and contemporaneous medical attendance, but no immediate definitive imaging (e.g. no CT/MRI) because plain x-rays were normal or were not diagnostic [21, 24].
The worker continues to have intermittent symptoms over many years but does not frequently seek specialist care, yet has evidence of ongoing analgesic use and episodic flare-ups [12–13, 14].
Later imaging (years after the incident) reveals disc pathology consistent with the claimant’s historical complaints (e.g. degenerative change followed by later prolapse on CT) [22–23].
Expert witnesses disagree on causation where one links the original traumatic event to a long-term vulnerable disc and recurrent problems, and the other ascribes later problems to progressive degeneration; the tribunal will decide which expert to prefer by reference to the totality of evidence, including the claimant’s credibility [23–25].
Statistical or epidemiological studies are relied upon by an expert to support a degenerative explanation; the tribunal will treat such studies as informative but not dispositive for an individual claimant [26].
How later courts have treated it
This is a single Administrative Appeals Tribunal decision applying established High Court authority (Stramare) and a state decision on statistics (Laube). The tribunal self-consciously applied accepted principles: commonsense causation, careful weighting of expert evidence, and scepticism about over-applying group statistics to individuals. Subsequent courts and tribunals typically follow the same analytical pattern when resolving conflicting medical opinions and late radiological findings. Practitioners should treat the decision as a useful example of how to frame factual narratives, elicit concurrent expert admissions about radiology, and explain delays in treatment to preserve causation arguments.
(As this deep dive is grounded only in the judgment provided, it does not catalogue subsequent appellate treatment beyond the decision itself. Users should check later authorities for developments.)
Still-open questions
Degree of specificity required to link a traumatic annular tear to later degenerative progression and prolapse. The tribunal accepted Carney’s explanation on the evidence, but the line between trauma-initiated vulnerability and natural degeneration remains fact-sensitive. Future cases will continue to test the evidential thresholds for such causal links.
Temporal gaps and treatment delays. The tribunal accepted cultural and employment-related reasons for delayed specialist consultation. How courts will treat longer or less-well-explained gaps remains open; claimants should be prepared to provide contemporaneous or corroborative evidence where possible.
Role of evolving imaging technology. Imaging modalities and their interpretation evolve. This decision illustrates that lack of early imaging does not preclude causation findings, but changing standards for imaging and retrospective interpretation may affect outcomes in other cases.
Weight to be afforded to statistical studies versus mechanistic explanations. The tribunal cautioned against over-reliance on group statistics. However, in cases where mechanistic expert evidence is weak or equivocal, tribunals may place more weight on epidemiological evidence. Boundaries between these approaches will be litigated further.
Practical takeaways for practitioners and medical experts:
Elicit and document a clear contemporaneous history when the injury occurs, including immediate symptoms and inability to work [7].
If later imaging is used to support causation, ensure experts explain how the radiological findings relate mechanistically to the earlier event, and address alternative degenerative explanations [22–25].
Anticipate and address delays in presentation with credible explanation supported by evidence where possible (e.g. analgesic use, work pressures, cultural factors) [12–13].
Remember that group statistics are supportive but rarely dispositive on individual causation; frame statistical evidence as contextual rather than determinative [26].
This decision is a practical illustration of applying Stramare’s commonsense causation approach in the workers’ compensation context, weighing lay evidence and concurrent expert admissions about imaging, and being cautious about importing group-level statistics into individual causation findings.
Judgment (27 paragraphs)
[1]
Yun and Comcare [2009] AATA 126 (26 February 2009)
(a) sets aside the decision under review and in place of that decision, decides that the respondent is liable for compensation pursuant to the Safety, Rehabilitation and Compensation Act 1988 (Cth) in respect of the injury sustained on 24 December 1990 as claimed by the applicant on 20 March 2006;
[4]
(b) reserves liberty to apply within 14 days in relation to the costs of the proceedings; and
[5]
(c) orders that in the absence of such an application within that period, the respondent pay the costs of the proceedings.
[6]
COMPENSATION - Commonwealth employee - nurse sustained back injury in 1990 - conflict of medical evidence - relevance of lay evidence in resolving conflict - concurrent evidence as to CT scans - relevance of statistical evidence - decision under review set aside.
In February 1991 the applicant, Neang Yun, claimed compensation for an injury that he sustained on 24 December 1990 in the course of his employment at the Royal Canberra Hospital. In April 1991 Comcare accepted liability for acute lumbo-sacral muscle and ligament strain pursuant to s 14 of the Safety, Rehabilitation and Compensation Act 1988 (Cth) (the Act).
In March 2006, Mr Yun made a further claim for ongoing compensation for medical expenses and incapacity payments on the grounds that he was still suffering the effects of the injury that he sustained on 24 December 1990. Comcare rejected the claim and this was confirmed on reconsideration. Mr Yun has applied to this tribunal for review of the decision on reconsideration.
[11]
The issue before me is whether the incapacity for work and medical expenses that are the subject of the current claim for compensation are the result of the injury that Mr Yun sustained on 24 December 1990.
[12]
I make the following findings of fact from the evidence of Mr Yun. I found him to be a frank witness who gave an honest account of the circumstances in which his injury occurred, and of the after effects of his injury.
Mr Yun was born in Cambodia, and is currently aged 55. He gave evidence of the grave difficulties that he encountered when he was living in Cambodia during the period of the Pol Pot regime. He was forced to flee Cambodia with his wife, and went to a camp in Thailand where he worked for the International Red Cross. He finally left Thailand and came to Australia in 1983 with his wife and two young children as a refugee. He said that his years in Cambodia and Thailand were very unsettled and unsafe. There was no social security, healthcare or education system, and no social structure at all, and many people were required to carry out hard work that they were not used to and died or became sick.
After participating in a refugee program and assisting the teaching of the Khmer language in Canberra, Mr Yun began studying nursing. In 1986 he commenced work on a part-time basis as a registered nurse at the Royal Canberra Hospital, and remained in that employment until 9 August 1996.
On 24 December 1990 he sustained an injury to his lower back at the Royal Canberra Hospital as a result of lifting and turning a heavy disabled patient with the assistance of two other nurses. He said that he experienced a sharp stabbing pain in his lower back as he bent and lifted the patient, and also experienced immediate pain down his left leg. He collapsed and could not get up from the floor due to the severe pain. He immediately stopped work and had to be assisted into a wheelchair. He was taken to the Casualty Department, where he had an x-ray and was examined by a doctor who gave him an injection for pain. He remained in hospital overnight.
He was very incapacitated and confined to bed for a week after his injury. He continued to be treated at the Royal Canberra Hospital and by a general practitioner for the next six weeks. The treatment consisted of rest, medication, physiotherapy and hydrotherapy.
He was then certified fit to return to work on 15 February 1991. After that he returned to full hours but remained on very light duties. Over a period of several months he progressively returned to full unrestricted nursing duties, but remained very careful in the way that he carried out those duties as he continued to have ongoing difficulties with his lower back and left leg. He experienced regular aching in his lower back and a tingling sensation in his left leg.
[13]
"64. I continued to work without complaint even though I regularly experienced pain. I was concerned that if I was unable to do my full duties I would lose my job. The discomfort was also spasmodic and on most days I could carry out my duties without restriction.
...
[14]
66. I felt as though I had to work harder to be accepted within the team in the hospital environment as well as socially outside of the workplace. Complaining was not part of my culture. I was very happy to be living in a country which was safe, provided medical services, provided education and ongoing employment with a wage to be paid for work carried out. I also had access to pain relief if needed.
67. I also considered that the ongoing difficulties I was having with my back were insignificant compared to the difficulties I had experienced in my life in Cambodia and Thailand and did not consider that there was any benefit in raising complaints in relation to my back during the course of my employment." (exhibit A1, page 8)
After arriving in Adelaide, Mr Yun worked as an interpreter on a part-time basis. He experienced ongoing discomfort in his lower back, and in about 2001 experienced an episode of severe pain when he was performing his normal work. He consulted Dr Daniel. His symptoms eased but flared up again in 2002 and he was then referred to an orthopaedic surgeon, Dr Ghan. CT scans were undertaken in March and August 2002. He had further flare ups in 2004 and 2006. His current treatment involves pain-killing tablets, meditation and a medicated plaster which provides a slow release of pain medication.
[15]
Section 14(1) of the Act provides for compensation for injuries suffered by employees of the Commonwealth, Commonwealth authorities or licensed corporations, and provides as follows:
[16]
"14(1) Subject to this Part, Comcare is liable to pay compensation in accordance with this Act in respect of an injury suffered by an employee if the injury results in death, incapacity for work, or impairment."
[17]
Section 16 provides in effect that where an employee suffers an injury, Comcare is liable to pay the appropriate cost of reasonable medical treatment obtained in relation to the injury.
Section 19 provides for compensation by way of incapacity payments where an employee is incapacitated for work as a result of an injury.
The requisite connection between the injury and employment appears in the definition of "injury" in s 4(1) of the Act. This provides relevantly that injury means:
[18]
"(b) an injury (other than a disease) suffered by an employee, being a physical or mental injury arising out of, or in the course of, the employee's employment; or ..."
[19]
Exhibit R3 includes records from the Royal Canberra Hospital of Mr Yun's treatment for the injury he sustained on 24 December 1990. The record is consistent with his evidence. It confirms that he had pain and was tender in the lower back, and had numbness and pins and needles initially in both legs, but persisting in the left leg. Medical certificates certifying incapacity for work were issued by the general practitioner whom Mr Yun consulted. He described his condition as a lumbosacral strain. The records of that practitioner, and of a second general practitioner whom Mr Yun also consulted, have, however, been destroyed.
Two specialists, namely Mr Paul Carney, a neurosurgeon, and Dr Peter Stevenson, a consultant physician, gave evidence of their opinions as to the nature of the injury sustained by Mr Yun and its relevance to his present condition. They expressed differing opinions as to whether the injury that Mr Yun sustained in 1990 was a prolapse of the L5/S1 disc.
They gave helpful concurrent evidence as to the significance of the available radiological evidence, and this helped to crystallize the extent to which their opinions differed, and the basis of their difference of opinion. They agreed that a plain x-ray taken at about the time of the injury would not reveal a prolapse, and the fact that the x-ray report was normal was of no significance to the issue as to which their opinions differed. They also agreed that a CT scan of 8 August 2002 showed a large left-sided prolapse of the L5/S1 disc.
An earlier CT scan of 22 March 2002 did not show a disc prolapse. However, both doctors agreed that that scan showed degenerative changes at the L5/S1 level, in that there was some narrowing of the disc and evidence of calcification. Mr Carney thought that some scarring was also apparent, but Dr Stevenson did not agree with that.
Whilst both doctors agreed that the cause of the abnormal narrowing of the L5/S1 disc as shown by the March 2002 CT scan was consistent with either non-specific degenerative change or a traumatic injury, Mr Carney thought it more probable that Mr Yun had suffered a prolapse of L5/S1 disc at the time of the injury in 1990, and that this had caused the abnormality in the L5/S1 disc. He concluded that whilst Mr Yun had (on the history he obtained) partially recovered with very conservative treatment and there had almost certainly been some healing of the disc space, Mr Yun had sustained a tear in the annulus and had suffered intermittent recurring bouts of compression and pain. The particular aspects of Mr Yun's history which Mr Carney regarded as significant were the unusual lifting of the patient, in that the patient was heavy and difficult and the lifting was done in a bent position; there had been an instant onset of severe pain that radiated down the left leg; Mr Yun had been confined to bed for a week after the event, and needed several weeks off work; the lower back pain had been associated with sciatica; and Mr Yun had had continuing symptoms as from that time on, both in the lower back and the left leg. Mr Carney said further that in his opinion, the recent episodes of severe symptoms were attributable to a recurrence of the prolapse, and there was evidence of nerve root compression and scarring. He said that once a person had had a disc rupture, they were always at risk of recurrent rupture, and once the disc was weakened, less significant events such as a sneeze, severe bout of coughing, or lifting a weight which was not heavy could provoke another rupture. Further, residual scarring following the healing of the annulus could cause episodes of pain.
[20]
"... I am clearly of the opinion that the statistical fact that a particular proposition is true of the majority of persons cannot of itself amount to legal proof on the balance of probabilities that the proposition is true of any given individual. The fact that most people with a blood alcohol level of 0.15 per cent are incapable of exercising effective control of a motor vehicle does not establish against any individual with that blood alcohol level that that individual is so incapable."
[21]
Evidence was also given by Mr Yun's general practitioner, Dr Daniel. Whilst he acknowledged the difficulties of determining the relevance of the injury that Mr Yun had suffered 10 years earlier in Canberra, he gave evidence of having obtained a history from Mr Yun that was consistent with the proposition that his more recent relapses and flare-ups of symptoms were attributable to the injury on 24 December 1990. He agreed that if there was a tear of the annulus then, the disc would have been left in a vulnerable state, and his evidence was generally consistent with the views expressed by Mr Carney.
In March v E & M H Stramare Pty Ltd[1991] HCA 12; (1990-91) 171 CLR 506, Mason CJ referred at 515 to the common law tradition that questions of causation must be determined by applying commonsense to the facts of each case. In doing so, and in considering the competing opinions of the doctors, I must take into account the totality of the evidence, including not only the medical evidence, but also of course the evidence of Mr Yun and the documentary material before me. Approaching the matter in that way, I am satisfied that the incapacity and medical expenses that are the subject of the claim for compensation referred to in the decision under review have resulted from the injury that Mr Yun sustained at the Royal Canberra Hospital.
[22]
(a) sets aside the decision under review and in place of that decision, decides that the respondent is liable for compensation pursuant to the Safety, Rehabilitation and Compensation Act 1988 (Cth) in respect of the injury sustained on 24 December 1990 as claimed by the applicant on 20 March 2006;
[23]
(b) reserves liberty to apply within 14 days in relation to the costs of the proceedings; and
[24]
(c) orders that in the absence of such an application within that period, the respondent pay the costs of the proceedings.
Date/s of Hearing 19 and 20 November 2008 and 16 February 2009
[27]
Solicitor for the Respondent Australian Government Solicitor
Parties
Applicant/Plaintiff:
March
Respondent/Defendant:
E & M H Stramare Pty Ltd
Legislation Cited (1)
Rehabilitation and Compensation Act 1988
Cases Cited (1)
(1984) 37 SASR 31
AI Analysis
Outcomeappellant
Disposition:
The tribunal set aside the decision under review and, in place of that decision, decided that Comcare is liable to pay compensation under the Safety, Rehabilitation and Compensation Act 1988 for the injury of 24 December 1990 as claimed on 20 March 2006; costs were reserved with an order for respondent to pay costs unless an application within 14 days was made (para 29).
From May 1991 his hours at the hospital increased to 48 hours per fortnight and fluctuated between 48 and 60 hours per fortnight. After the injury he took Panadeine Forte for 6 months or so, but stopped that medication because of abdominal discomfort. He then continued to take a minimum of 4 Panadol tablets nearly every day.
Prior to his injury, Mr Yun had commenced studying engineering part-time. He completed this course and obtained a diploma in engineering in 1995. After that he decided to move to Adelaide, and one of his reasons for doing so was that there were more opportunities to obtain work as an engineer in Adelaide than in Canberra.
He continued to take Panadol at the same rate after he moved to Adelaide. He said that he took the Panadol "to reduce the pain to a bare minimum that I could cope with" (transcript, page 13, line 29). He consulted his current general practitioner, Dr Daniel, in 2001, and in March 2002 Dr Daniel arranged a CT scan and referred him for physiotherapy. Mr Yun said that over the period from the date of injury until he saw Dr Daniel, the pain in his back was constant, and he also had pain in his left leg all along, although the pain in the back was worse. However, he did not take any time off work because of his back between when he returned to work in February 1991 and until after he began seeing Dr Daniel.
In his written statement Mr Yun provided the following further information as to the work he did at the hospital before he resigned to come to Adelaide.
Mr Carney said further that the fact that the doctors treating Mr Yun in 1990 had not requested a CT scan did not necessarily suggest that they did not consider that he had suffered a significant disc injury or significant sciatica. He said that it would have been reasonable for the doctors then involved to have waited to see what happened, and if Mr Yun recovered progressively, they might reasonably have decided that they did not need to do a CT scan.
I prefer Mr Carney's conclusion to the contrary view which Dr Stevenson expressed, namely that Mr Yun's recent pain and disability is due to the natural progression of non-specific degeneration of the lower spine. Dr Stevenson said that the main reason for his having reached a different conclusion from Mr Carney was the difference in the history that he had relied on. In reaching his opinion, Dr Stevenson regarded it as important that there was no sufficient evidence of ongoing back or leg pain after Mr Yun returned to work, or that he had sought on-going medical treatment for problems with his lower back until 2001. However, Mr Yun gave evidence as to his continuing low back pain and sciatica, and of the medication he had taken over the years after the accident, and I accept that evidence. Further, Mr Yun said that he had not sought medical treatment for his continuing symptoms during his continuing work at the Royal Canberra Hospital and prior to his consulting Dr Daniel in 2001, but he explained his reasons for putting up with his symptoms during his continued employment in Canberra in his witness statement (see paragraph 13 above).
Dr Stevenson also based his opinion to some extent on various surveys of persons who have suffered symptoms of disc degeneration in the light of MRI scans. Whilst such studies are informative and relevant, statistical evidence does not necessarily apply to any particular individual, and it is ultimately necessary for me to determine this matter by reference to the whole of the evidence before me. The limitations on the use of statistical evidence were referred to in State Government Insurance Commission v Laube(1984) 37 SASR 31, where a former Chief Justice of the Supreme Court of South Australia said, at [33]: