Section 361 reverse onus requires that objective facts be established by the applicant to suggest a contravention before the presumption is enlivened; it does not relieve the applicant of proving factual circumstances (such as membership of an industrial association, participation in lawful activities, or exercise of workplace rights) upon which the contravention is alleged to rest.

Where an employer is alleged to have contravened Part 3-1 of the Fair Work Act and the s 361 reverse onus has been enlivened on objective facts, it is normal or usual for the employer to call evidence from the actual decision-maker to explain what actuated their conduct; failure to do so, in the context of the adverse action taken, is relevant to whether the employer has discharged the evidential onus cast by s 361.

A finding of fact by a trial judge based on credibility is not to be set aside on appeal unless it can be shown that the trial judge has failed to use or palpably misused his advantage or acted on evidence inconsistent with facts incontrovertibly established or glaringly improbable.

Section 361(1) creates a rebuttable presumption that adverse action was taken for a proscribed reason unless the respondent proves otherwise, with the purpose of throwing the onus onto respondents to prove that which is peculiarly within their knowledge.

To rebut a presumption under s 361, a party must establish on the balance of probabilities that the alleged improper reason was not a reason for the action.

The s361 statutory presumption that a reason for taking adverse action was the exercise or proposed exercise of a workplace right is extremely difficult to displace if no direct testimony is given by the decision-maker acting on behalf of the employer.

A person takes action for a particular reason under s360 if the reasons for the action include that reason; and where multiple reasons exist, action is taken for a prohibited reason if the reasons include that prohibited reason.

Under s361, where an employee alleges adverse action for a prohibited reason, a presumption arises that the action was taken for that reason unless the employer proves otherwise. The onus lies on the employer to prove that its conduct was not motivated in whole or in part by the prohibited reason.

The task of a court in determining whether adverse action was taken for a prohibited reason is to determine why the person took the adverse action and ask whether it was for a prohibited reason or reasons which included a prohibited reason. The question is whether a prohibited reason was a 'substantial and operative' reason for the respondent's action.

Direct testimony from a decision-maker which is accepted as reliable is capable of discharging the burden upon an employer to prove a non-prohibited reason, even though an employee may be a member of an industrial association and engage in industrial activity.

A finding of fact by a trial judge based on credibility is not to be set aside on appeal unless it can be shown that the trial judge 'has failed to use or has palpably misused his advantage' or has acted on evidence which was 'inconsistent with facts incontrovertibly established by the evidence' or which was 'glaringly improbable'.

Section 361 establishes a rebuttable presumption that adverse action was taken for the reason alleged if taking such action for that reason would constitute a contravention of Part 3-1. An alleged contravener must prove that none of its substantial and operative reasons for the adverse action was to prevent the exercise of workplace rights.