Gibbons v C&M Plant Hire Pty Ltd Trading as C&M Plant Hire

This matter concerned an employer's onus under section 361 of the *Fair Work Act 2009* (Cth) in determining whether adverse action was taken for a proscribed reason. The court was required to consider the evidence presented by the employer to discharge this onus, particularly in light of the principle that mere declarations of an innocent reason for adverse action may not suffice if contrary inferences can be drawn from the facts.

The central legal issue was to determine the relevant decision-maker and the basis of their decision when adverse action is taken. The court considered whether the employer could discharge its onus by relying solely on the evidence of the decision-maker, or if it was necessary to examine the reasons of those who made recommendations leading to the adverse action. This involved assessing how the "mind" of a corporate employer is ascertained and whether the improper purpose of one individual could taint the decision of another, particularly in situations involving multiple decision-makers or a chain of recommendations.

The court applied principles established in cases such as *Barclay*, *Tsilibanks v Transfield Services (Australia) Pty Ltd*, *Voigtsberger v Council of the Shire of Pine Rivers (No 2)*, and *Wood (on behalf of the Industrial Relations Bureau) v Lord Mayor, Councillors and Citizens of the City of Melbourne*. These authorities highlight that the question of why adverse action was taken is a question of fact to be determined in light of all established facts. The onus is on the employer to prove that the action was not taken for a prohibited reason, and this onus may not be satisfied by mere assertions if contradictory evidence or inferences exist. The court emphasised that it is appropriate to have regard to the reasons actuating those who made recommendations to the ultimate decision-maker, not just the reasons of the ultimate decision-maker themselves, especially where the decision-maker may have merely "rubber-stamped" a prior recommendation.