Impiombato v BHP Group Limited (No 2)

In the case of Impiombato v BHP Group Limited (No 2), the Full Court of the Federal Court of Australia was tasked with deciding a dispute concerning the allocation of costs following a successful appeal in part and a dismissal in part. The appellant, Impiombato, sought a costs order in its favour, while the respondents, BHP Group Limited, sought apportionment of costs on an issue-by-issue basis. The legal issues before the court involved the principles governing the award of costs in cases where the outcome is mixed, and the appropriate allocation of costs when one party is successful on some issues but not on others.

The court considered the principles relevant to the award of costs in mixed outcome cases, noting that the applicants had argued for separate costs orders for each issue, with the unsuccessful party on each issue paying the other party's costs. Alternatively, the applicants submitted that each party should bear its own costs, considering the mixed success of both parties and the time dedicated to both issues. The court found that while there were two categories of amendments in the amendment application, the arguments before the court did not distinctly separate these categories. Instead, the court held that the two categories of amendments were argued together, and therefore, the mixed outcome of the appeal justified a single order for costs.

In making its decision, the court took into account several factors, including the fact that the applicants were responsible for initiating the amendment process, BHP did not oppose the amendments themselves but only the application to relate the amendments back to the commencement of the proceeding, and BHP was successful on the more significant questions, including the principles to be applied to the group definition amendments and the factual questions of mistake and prejudice. The court concluded that while BHP was predominantly successful, the percentage of costs should be reduced to reflect BHP's failure in its opposition to the additional claims amendments taking effect from the commencement of the proceeding.

The court ordered that the applicants pay 50% of BHP's costs of the application before the primary judge and on the appeal. This order was made to reflect BHP's predominant success, while also reducing the percentage of costs to account for the applicants' success on the additional claims amendments. The court set aside previous orders and replaced them with new orders specifying the costs to be paid by the applicants and respondents, respectively.