Maurice Blackburn Cashman v Brown

The High Court of Australia considered a dispute between Maurice Blackburn Cashman (the plaintiff) and Brown (the employer, the defendant) concerning a claim for damages for injury, including psychiatric injury, allegedly suffered by the plaintiff as a result of the employer's negligence. The plaintiff had made a claim for non-economic loss under section 98C of the *Accident Compensation Act 1985* (Vic). Following a referral of questions to a Medical Panel under section 104B(9) of the Act, the plaintiff was deemed to have a "serious injury" for the purposes of the Act, entitling her to commence common law proceedings for damages under section 134AB(2). The employer denied the plaintiff had suffered injury, loss, and damage, leading to the plaintiff pleading issue estoppel in her amended reply to the amended defence.

The central legal issues before the High Court were whether the employer was precluded by the operation of the *Accident Compensation Act 1985* (Vic) from making certain contentions in evidence or argument, and whether the employer was so precluded as a matter of issue estoppel. Specifically, the court was asked to determine if any estoppels pleaded by the plaintiff arose, if the court was obliged to accept as final and conclusive certain matters pleaded by the plaintiff, and if the defendant was precluded from acting in ways claimed by the plaintiff. These questions arose from the plaintiff's assertion that the Medical Panel's finding of a "serious injury" under section 68(4) of the Act, which states the Medical Panel's opinion is to be applied by "any court, body or person" for determining any question or matter, created an estoppel against the employer in the common law proceedings.

The High Court held that the issue estoppels alleged by the plaintiff did not arise from the Medical Panel's opinion. The court reasoned that the opinion of a Medical Panel, while binding for the purposes of determining whether a "serious injury" threshold has been met for statutory compensation entitlements, does not operate as an issue estoppel in subsequent common law proceedings for damages. The court found it unnecessary to consider further questions regarding who is affected by a Medical Panel's opinion or whether such an opinion constitutes a "decision" between parties, as the primary basis for the estoppel claim was unfounded. Consequently, the appeal was allowed, the order of the Court of Appeal of the Supreme Court of Victoria was set aside, and the reserved questions were answered in favour of the employer, stating that no such estoppels arose and the court was not obliged to accept the plaintiff's pleaded matters as final and conclusive. The appellant was ordered to pay the respondent's costs of the appeal to the High Court.