McKay v WorkCover/Allianz Australia

1. Ultimately there was no dispute about a number of matters and facts relevant to the resolution of the dispute. In particular the evidence established that:-
   • At the time of death the worker was aged 43 years and had been employed in the classification of Sheeter for some time.
   • The sheeter machine is essentially one which cuts pieces of paper to a specified dimension from a large roll of paper. The activities of the Sheeter in broad terms involve positioning the roll of paper which weighs in the order of 1060 kg with the aid of a forklift in the vicinity of grips at one end of the machine, rolling the paper into position between the grips, engaging the grips mechanically, feeding one end of the roll into the machine, starting the operation of the machine, monitoring its operation checking the dimensions of the paper cut on an occasional basis and when the roll has been cut into pieces which have been deposited onto a pallet at the other end of the machine stopping the machine and removing the pallet with the aid of a hand operated pallet lifter.
   • The worker died in the course of his employment with the employer.
   • The worker had a family history of heart disease his father having died as a result of a myocardial infarction at the age of 44 years. The worker himself survived a myocardial infarction in 1991 at the age of 36 and for some time prior to his death had suffered elevated cholesterol, and from hypertension albeit controlled by medication and was a smoker.
   • The factors referred to immediately above suggest that immediately prior to his death the worker had a significant level of coronary artery disease (Dr Craig tr 3, 16); see also to similar effect the evidence of Dr Mahar at tr 20 and Dr Sangster at BD 62.
   • The worker was found lying on his back near the sheeter machine without the sign of a pulse at about 10.45 pm on 3 August 1998. He had had a brief conversation with a fellow employee Shannon Sando shortly prior to being found. Sando said that there appeared to be "'no problems' with ... [the worker] ... and that he seemed okay". Sando thought that "...[the worker's] ... death must have occurred within 5 minutes or so". (BD 47
   • The worker's death resulted from the aggravation, acceleration, exacerbation, deterioration or recurrence of pre-existing coronary heart disease.
2. Given the last mentioned matter and the fact that the worker was in the course of his employment with the employer when he died it will be presumed in the absence of proof to the contrary that the worker's employment contributed to his death; s 31(5) of the Act.

The Medical Evidence and Further Findings Therefrom

1. In terms of the medical evidence generally speaking I have a preference for the opinions of Drs Mahar and Sangster where they differ from that of Dr Craig. In my view the last named although not differing in many respects from the opinions of the former was less detached and objective and tended towards advocacy on the applicant's behalf. Taking those factors into account and the general impression Dr Craig made on me in giving evidence I consider the value of his contribution to the debate diminished in some respects.
2. I am satisfied from the evidence of Dr Sangster that the worker "suffered from many of the factors commonly associated with the increased risks of heart attack. These included a family history of premature coronary heart disease, previous myocardial infarction, resumption of his previous smoking habit, treated hypertension and treated hyperlipidaemia. It is well recognised that each of these factors contributes significantly to the risk of myocardial infarction and increase the risk of recurrent infarction in people already suffering from coronary artery disease (that is previous myocardial infarction)"; (Exhibit R3 par 1; see also BD 62 par 1).
3. I also find on the basis of the evidence of Drs Sangster and Mahar that is it probable that the events leading to the worker's fatal myocardial infarction were "a sudden cardiac arrythmia which was the result of acute ischaemia, which in turn ... resulted from a sudden occlusion of one of his coronary arteries." (BD 68, tr 20).
4. Although it is the case that little is known of what activities the worker was engaged in during the five to ten minutes before his death ("the subject period"), there was a general consensus that if he was doing his usual work on the sheeter in that period "on the balance of probabilities, given all the other risk factors in his case, there was no causal link between ... [the worker's] ... work and the cause of his death; Dr Craig tr 14, Dr Sangster BD 62 par 3. In those circumstances it "is likely that ... [the worker's] ... sudden death was inevitable as part of the natural history of his coronary artery disease". (BD 62) On the other hand if the worker had been doing extraordinarily heavy work in the course of his employment in the subject period his employment duties may well have contributed to the myocardial infarction and his death; Dr Sangster BD 62, Dr Mahar tr 24. I add that Dr Craig suggested that mental stress in terms of "a problem with his [the worker's] machine" (tr 12) may also have played a part in his death. He also suggested that such stress need not be great such as "fear or extreme agitation" and that an exercise in mental arithmetic would be sufficient to produce cardiovascular responses sufficient to trigger the events leading to the infarction. However I prefer the evidence of Dr Mahar on this aspect who said that mental stress was only rarely involved as a factor in the causation of myocardial infarction and if it was to be involved it would need to be "acute tremendous stress". (tr 22)
5. Whilst as noted there was general agreement that if in the subject period the worker was performing the normal work of a Sheeter the work was probably not implicated in his death, there is no evidence of what the worker was doing in that period. In his report of 8 May 2000 (BD 63) Dr Craig having seen the video demonstrating the work of a Sheeter adverted to:-

"... a number of possibilities for the machine and the whole work practice to malfunction for example: The rolls are large and need to have ends taken off their spindles. It would appear possible for sticking there. It would appear possible for mal-alignment in the machine. It would appear possible than (sic) when he moves the paper around although the workman who demonstrated used small loads of paper that he could have picked up much larger loads of paper and I am sure there are other possibilities that I have not considered."

1. Dr Craig elaborated further on those possibilities in evidence (tr 16) as follows:-

"Q Could you just have a look at that letter first, doctor. Now, in your report you refer to some possibilities of malfunction of the machinery.

1. Q Am I right in thinking that these possibilities were your own invention. There was no evidence that was put to you that would suggest any of these events had occurred.
2. A Yes. Well, I looked at the video. I thought about the machinery, I thought about the size of the paper, wheels. I run a farm; I thought of things that go wrong on the farm, and I just thought it was possible, if it was something like that, things could go wrong. So yes, they are my invention." (emphasis mine)

1. The essence of the submission of Mr Martin of counsel for the applicant was that the evidence of Dr Craig in particular raised the possibility that sheeter machine may have malfunctioned in the subject period involving the worker in exertion sufficient to precipitate his fatal myocardial infarction. Mr Martin argued that in the absence of the respondent leading evidence negating those possibilities or that malfunctions happened only infrequently the respondent had not discharged the onus cast upon it by s 31(5).
2. The difficulty I have with the argument of Mr Martin is that it depends for its efficacy on the proposition that the possibilities adverted to by Dr Craig have some credibility. Dr Craig was hardly in a position to give expert evidence on the ways in which the sheeter machine may malfunction or on the proposition that a malfunction would lead inevitably to extraordinarily heavy work on the part of the Sheeter sufficient to precipitate myocardial infarction. Moreover his evidence as to the basis for the scenarios he raised were to my mind manifestly unconvincing in light of my impression of the job as depicted in the photographic and video evidence and his concession in evidence that they were his invention. All in all it seems to me his views amounted to no more than conjecture or speculation.
3. In the circumstances I find myself in much the same position as Her Honour Judge Parsons DP did in Lewis v WorkCover/Allianz Australia (Horwood Bagshaw Australia Ltd) [2001] SAWCT 87 and with respect I adopt the approach of Her Honour at par 28. In the result I am left with the situation that the worker was a person significantly at risk of myocardial infarction because of the non-work factors canvassed earlier in these reasons and as a result his death could well have been "inevitable or as part of the natural history of his coronary artery disease". (BD 62) Whilst work activity could have contributed to the infarction it would need to have been extraordinarily heavy and probably undertaken in the subject period. I am satisfied his usual work as a Sheeter was not heavy and was unlikely to have caused his death. Suggestions of the sheeter machine malfunctioning resulting in the worker undertaking strenuous activity are unconvincing being no more than conjecture or speculation.
4. I find on the balance of probabilities that the worker was not engaged in extraordinary physical activity or subject to "acute tremendous stress" in the subject period and therefore that his employment did not contribute to his death.
5. In those circumstances the respondent has discharged the onus cast on it by s 31(5) of the Act and the appropriate order is that the determination of WorkCover rejecting the claim for compensation be affirmed and the claim for compensation be dismissed.

Parties are advised that if a party wishes to appeal against any part of this decision which is appealable pursuant to s 86(1) of the Act such appeal must be filed with the Registrar in accordance with the form titled Notice of Appeal within 14 days of the delivery of this decision and must be served on all parties.