Failure to give sufficient reasons
8 The first and primary ground of appeal is that the Tribunal failed to refer to the evidence or other material that was the basis for its finding that CAD did not contribute to Mr Byrne's death. Mrs Byrne submits that the Tribunal gave no reasons or no sufficient reasons for that conclusion as required by s 43(2B) of the Administrative Appeals Tribunal Act 1975 (Cth).
9 It is necessary to have some understanding of the context of the Tribunal's conclusion and the structure of the Tribunal's decision. The Tribunal considered the whole of the evidence before it, then gave its reasons and consideration under consecutive headings.
10 Under the heading '[c]onsideration of "kind of death"' the Tribunal found that the "kind of death" was, on the balance of probabilities, drowning. The Tribunal stated at [57] that it did not consider IHD or CAD was a "kind of death". It then proceeded to discuss the conflicting medical opinions about the kind of death and whether a cardiac event arising from CAD caused the death. In particular, it engaged in a detailed analysis of the evidence concerning the effect of IHD or a cardiac event arising from CAD. At [64] - [68] the Tribunal weighed the evidence on a cardiac cause of death. Accepting that Mr Byrne had CAD (at [66]), the Tribunal was not satisfied on the balance of probabilities that it was a cause of death or a "kind of death" (at [68]) for reasons that it gave by reference to the evidence and its assessment of it. In summary, it referred to the two premises on which the opinions that there was a cardiac cause of death were based. Those premises were that the autopsy revealed that Mr Byrne had no water in his lungs and that he had made no effort to save himself. The Tribunal did not accept that either premise was correct, so that the opinions based on those premises were without foundation.
11 The next heading in the decision reads '[i]s there a reasonable hypothesis connecting Mr Byrne's death with his service?' The Tribunal noted that, initially, two hypotheses had been advanced relating to malaria and IHD and that a third hypothesis was advanced during the hearing. That hypothesis was, as I have noted, that CAD impaired Mr Byrne's ability to survive once he was in the water. No complaint is made about the Tribunal's treatment of the first two hypotheses in this appeal.
12 The Tribunal proceeded to consider the applicable principles. There is no criticism of the statement by the Tribunal of those principles.
13 Despite having concluded that it was not satisfied on the balance of probabilities that CAD was a cause of death, the Tribunal reiterated the conclusions in the medical evidence in support of the third hypothesis that CAD was a cause of death and found that this was a reasonable hypothesis connecting Mr Byrne's death with his war service (at [88] - [89]).
14 Mrs Byrne points to the Tribunal's finding at [66] that CAD was not a cause of death on the balance of probabilities. She submits that this left open the possibility that the contribution of CAD to Mr Byrne's inability to survive once in the water was sufficient for the purposes of s 120(1) of the Act, to establish that the death was "war-caused" within s 8 of the Act. The Tribunal did not, however, stop its analysis at that stage of its reasoning. It rejected the premises on which the possibility was based. It specifically considered whether it was satisfied that Mr Byrne's death did not arise out of a cardiac event and concluded, in the light of all of the evidence, that it was so satisfied.
15 The Tribunal acknowledged (at [90]) that, having found a reasonable hypothesis, Mrs Byrne's claim would succeed unless the hypothesis was disproved beyond reasonable doubt in accordance with the principles enunciated in Byrnes at 571 and noted in the Tribunal's decision. It then stated at [91]:
'Having considered all the evidence, we are satisfied beyond reasonable doubt that Mr Byrne's death did not arise out of and was not attributable to a cardiac event of a kind described by Associate Professor Richards, Dr Craig, Dr Freeman or Dr Burn, that is, a cardiac event that was a consequence of IHD or CAD.'
That was the evidence considered in detail under the heading "consideration of the kind of death".
16 The Tribunal expanded on that conclusion with respect to IHD at [92] and, at [93] said:
'The opinions relating death to IHD and CAD were based essentially on there being no water in Mr Byrne's lungs and his "inability" to save himself. Those opinions concluded that death was caused by such a cardiac event rather than by drowning. On the evidence, we are satisfied beyond reasonable doubt that Mr Byrne drowned, and that neither IHD nor CAD contributed to his death.'
'[T]he evidence', as referred to in that paragraph, clearly refers back to the detailed discussion of the evidence earlier in the Tribunal's reasons. It was that evidence which disproved the hypothesis that Mr Byrne's ability to survive in the water was impaired by war-caused CAD.