State Insurance Office v CMT Construction of Metropolitan Tunnels

The applicant, the State Insurance Office, sought special leave to appeal to the High Court of Australia from a decision of the Full Court. The dispute concerned whether a workers' compensation insurer, having indemnified an employer for payments made to an injured worker, could recover those payments from the employer after the worker had successfully obtained and satisfied a common law judgment against the employer. The Full Court had held that once the common law judgment was satisfied, the employer's liability to pay workers' compensation was extinguished *ab initio*, allowing for the recovery of payments made.

The central legal issue before the High Court was whether the Full Court's finding that the employer's workers' compensation liability was extinguished *ab initio* was consistent with section 79 of the relevant Workers' Compensation Act. Specifically, the applicant argued that subsection (1A) of section 79, which outlines the consequences of a satisfied common law judgment, did not provide for the repayment of workers' compensation payments and was, in fact, inconsistent with the notion of liability ceasing *ab initio*.

The applicant contended that section 79(1A) stipulated that a worker's right to further weekly payments would cease and granted a discretion to refuse further awards, rather than extinguishing liability retrospectively. This was contrasted with the Full Court's interpretation, which implied a repayment obligation. The applicant relied on the reasoning in *XPOLITOS' case*, where it was noted that equivalent provisions did not require a worker to repay weekly payments already made. Furthermore, the existence of a discretion under section 79(1A) was argued to be inconsistent with an automatic extinguishment of liability *ab initio*, as such a discretion would be rendered unnecessary if liability had ceased from the outset.