Conclusion on the appeal
As to the first argument, we do not accept the appellant's construction of the expression "(other than a disease)". The word "disease" in that expression is used in its statutorily defined sense.
The matter can be approached in this way. In lay terms injury and disease are different concepts, notwithstanding that there may be some instances where the appropriate categorisation is problematic. But one would unhesitatingly speak of cancer or influenza as a disease and a broken leg or concussion as an injury.
Since both injury and disease are misfortunes which may have a relationship to employment, workers' compensation legislation has long provided for compensation in each case. But the necessary relationship to employment may be, generally speaking, less readily susceptible to proof of work connection for disease than injury.
The policy manifest in the drafting of the Act is to require a higher level of work connection in the case of disease. In the case of disease there has to be a contribution in a material degree by the employment. In the case of injury, it is sufficient to show that the injury arose out of or in the course of the employment - there need not be a causal connection.
Thus an employee seeking compensation, like Mr Burch, will naturally enough try first to show that he or she has suffered an injury (in the ordinary sense) because it will only be necessary then to establish that the injury arose in the course of employment. Such a claimant may, as an alternative, again like Mr Burch, seek to show that if what was suffered was not an injury in the ordinary sense, then it was a disease in the ordinary sense, and that there was contribution to a material degree by employment to that disease. This Mr Burch also attempted to do. He gave evidence as to alleged harassment in the workplace by fellow employees which contributed to his condition. But because he won on the first issue of injury (in the ordinary sense), it was not necessary for the Tribunal to reach any conclusion as to this alternative claim.
The definition of "injury" in s 4(1) is consistent with this analysis, although some confusion is caused because the alternative meanings of "injury" are set out in a somewhat illogical sequence. It would make more sense if the first possible meaning of "injury" was injury (in the ordinary sense) arising out of or in the course of employment. If an employee satisfied this lower test of work connection there would be no need to go any further. However, it is we think reasonably clear that the expression "(other than a disease)" is inserted to make it clear that par (b) of the definition, which requires only the lower level of work connection, is referring to something different from disease (in the statutory sense) referred to in par (a) which requires the higher level of work connection (contribution to a material degree).
As to the second argument, counsel for the appellant accepted that an injury in the ordinary sense did not necessarily require something external to the body. Such a concession was obviously correct. In Kavanagh v The Commonwealth (1960) 103 CLR 547 at 553 Dixon CJ said a rupture of the gullet was an "injury by accident". Such an episode was
"… a sudden destruction of tissue by force or pressure. It is true that the force or pressure was not exerted from without the body, but that I think makes no difference nor does it make any difference if it occurred, as it may have done, as a consequence of another organ of the body, namely the stomach, responding to a virus infection."
However the appellant's counsel in the present case argued that there could not be an injury in this sense without some "rupture" or "breaking" of some tissue. Here, counsel said, there was merely an occlusion, that is to say a blocking.
However the fact that cases such Kavanagh have accepted that an incident involving an internal rupture or breaking was an injury does not mean that, as a matter of law, rupture or breaking is an essential prerequisite to a finding of injury (in the ordinary sense) of an internal nature. In Accident Compensation Commission v McIntosh [1991] 2 VR 253 there is an extensive discussion of the concept of accident (in the ordinary sense) by Murphy J, a judge of great experience in workers' compensation. In a judgment in which Crockett and Cummins JJ concurred his Honour said (at 263):
"Long before the inclusion of these references to 'disease' in the definition of 'injury' [in the New South Wales legislation considered in O'Neill v Lumbey (1987) 11 NSWLR 640], claims for coronary occlusions, cerebral haemorrhage, ruptured aneurysms, aorta, oesophagus etc. had commonly been made and had succeeded if occurring during a protected period, on the basis that they were 'injury by accident', being clearly a physical injury - and accidental - being unexpected by the worker at the time that they occurred: cf. Clover, Clayton & Co. Ltd. v. Hughes [1910] A.C. 242."
His Honour went on to observe (at 264):
"It is a remarkable development that today it is being suggested that in an Act which has consistently demonstrated a widening of cover to a worker, (being in the nature of social insurance or security) the inclusion in the definition of 'injury' of references to disease contributed to by the employment has prompted argument that mishaps, formerly accepted without debate to be 'injury', are no longer to be so considered, but are rather to be characterised as the very disease to which they are due, and excluded, unless work contributes to them." (Emphasis in original)
McIntosh was approved by Toohey, McHugh and Gummow JJ who were members of the majority in Zickar v MGH Plastic Industries Pty Ltd (1996) 187 CLR 310 at 335. (Of course under the Act it is only necessary to show injury (in the ordinary sense), not injury by accident: Zickar at 319.)
Here the stroke was the injury. There was no contest as to what a stroke was. It was a disturbance of the normal physiological state (Hume Steel Ltd v Peart (1947) 75 CLR 242 at 252-3) or an ascertainable lesion or dramatic physiological change (McIntosh at 257).
In our opinion the appeal should be dismissed with costs.