For years, claims managers have been grappling with how to characterise an "injury" under workers compensation law—which is important because it determines whether a causal or merely temporal connection with employment is necessary to establish liability. The principles were fairly well settled until the Full Federal Court's decision in May v Military Rehabilitation and Compensation Commission [2015] FCAFC 93 appeared to expand the definition of "injury" to contain any "physiological change or disturbance of the person's normal physiological state (physical or mental)"—potentially including anything that was previously considered a "disease".
On appeal in Military Rehabilitation and Compensation Commission v May [2016] HCA 19 (May), the High Court endorsed the earlier position that "disease" and "injury (other than a disease)" (often referred to as "injury simpliciter") were two distinct categories of illness and that the precise nature of the physiological change is central in
