Abigroup Contractors Pty Ltd (Acn 000 201 516) v Sydney Catchment Authority (No 2)

Abigroup Contractors Pty Ltd (Acn 000 201 516) (Abigroup) sought to appeal a decision of the Supreme Court of New South Wales concerning the interpretation of an earlier court order. The Sydney Catchment Authority (SCA) was the respondent. The dispute centred on whether the court had the power to amend or clarify its previous orders under the "slip rule" to reflect the parties' understanding of the judgment.

The primary legal issue before the Court of Appeal was whether the Supreme Court had erred in refusing to amend its previous orders. Specifically, the court had to determine if the slip rule, which allows for the correction of clerical mistakes or errors arising from an accidental slip or omission in a judgment or order, extended to correcting what Abigroup argued was a misapprehension by the judge of the parties' agreement regarding the scope of the orders.

The Court of Appeal held that the slip rule is confined to correcting errors of form, not substance, and does not permit a judge to alter a judgment or order to reflect what the judge believes the parties intended or what the judge might have said in oral reasons if it differs from the formal orders. The court found that the judge had correctly applied the slip rule by refusing to amend the orders, as the application sought to change the substantive effect of the judgment rather than correct a clerical mistake or accidental omission. The appeal was therefore dismissed.