Principles governing circumstances where the reason or reasons relied upon include misconduct were recently considered in Farmer v KDR Victoria Pty Ltd T/A Yarra Trams:  FWC 6539 at .
“However in matters such as this, in which the conduct of the person is said to have involved misconduct, there is a need to subject the allegations to careful scrutiny, avoiding “inexact proofs, indefinite testimony, or indirect inferences”. Briginshaw v Briginshaw (1938) 60 CLR 336, per Dixon J. In considering the evidence, a “proper degree of satisfaction is required having regard to the seriousness of the allegations” Budd v Dampier Salt Ltd 166 IR 407;  AIRCFB 797 at ., noting that “the strength of the evidence necessary to establish a fact or facts on the balance of probabilities may vary according to the nature of what it is sought to prove”. Neat Holdings Pty Ltd v Karajan Holdings Pty Ltd (1992) 67 ALJR 170, per Mason CJ, Brennan, Deane and Gaudron JJ, at . In a case such as this involving misconduct the Commission must determine whether the conduct occurred.” Edwards v Giudice and Others  FCA 1836, -, per Moore J.
And see Sayers v CUB Pty Ltd (2016) FWC 3428 delivered 26 May 2016 per Clancy DP