A Mazzzaferro & Riverstone Pty Ltd T/as Family Medical Centre v Vozzo & 5 Ors

The appellants, A Mazzzaferro and Riverstone Pty Ltd trading as Family Medical Centre, appealed to the Supreme Court of New South Wales from a decision of the Workers Compensation Commission. The dispute concerned a claim for workers' compensation by the respondent, Vozzo, who had contracted HIV and AIDS during the course of her medical employment. The central difficulty was that the precise date and circumstances of her infection could not be identified, and she had been employed by multiple entities during the relevant period.

The primary legal issues before the Court of Appeal were whether the evidence supported the trial judge's finding that employment by the appellants was a cause of Vozzo's injury, and whether evidence of arithmetic probability could sustain a finding on the balance of probabilities. The court also considered the sufficiency of the evidence presented and whether the absence of detailed reasons from the Commission affected the appeal.

The Court of Appeal dismissed the appeal, finding that the trial judge's conclusion was open to be made on the evidence. The court accepted that while the precise date of infection was unknown, expert evidence had established a possible range of dates. This evidence, when considered in light of the fact that Vozzo had worked for the appellants during that period, was sufficient to support a finding on the balance of probabilities that her employment with the appellants was a contributing cause of her injury. The court held that the evidence of arithmetic probability, when properly understood, was capable of sustaining such a finding. The appeal was accordingly dismissed with costs.