The High Court has unanimously allowed an appeal against the decision of the Victorian Court of Appeal in Wingfoot Australia Partners Pty Ltd v Kocak, in which the VCA granted certiorari to quash a decision of a Medical Panel convened under the Accident Compensation Act 1985 (Vic). The VSCA made that order on the basis that the Panel’s reasons for its opinion were inadequate, particularly because the Panel failed to explain why it rejected expert medical opinion on Kocak’s injuries in favour of its own view. The High Court held that the Act required that an opinion of the Panel must be adopted and applied in the determination of all matters or questions arising under the Act. Certiorari was not available because the Panel’s opinion had been brought to a final resolution and thus had no continuing legal effect, and also because the opinion met the required standard as assessed by the trial judge.