The appellant, Mr Byrne was the Lodge President of the CFMEU at the Dawson Mine at Moura in central Queensland and employed on the mine. In that capacity the Mr Byrne had been involved with negotiating with the respondent employer in relation to a replacement enterprise agreement for the workers of the mine the year before the subject matter of the claim before the court.
The employee had applied at late stage for 2 days annual leave which coincided with Anzac Day 2014. The leave was declined because of low available crew numbers. A discussion took place on 22 April 2014 in response with his supervisor Mr Lawn, wherein Mr Byrne said he would take sick leave anyway:
 According to Mr Lawn’s evidence, which the primary Judge accepted, the conversation then proceeded in substance as follows:
Mr Byrne: Fine, I’m going to be sick anyway.
Mr Lawn: Mate, you have asked for annual leave, it is not within the time period, it’s not approved.
Mr Byrne: I will get a medical certificate. You will find that very hard to challenge.
Mr Lawn: If you get a certificate from a medical practitioner, that is fine but you have already told me that you are going to be sick. If you take sick leave, we will have to have a completely separate discussion based on the discipline policy.
Subsequently Mr Byrne called his supervisor and said he was unwell and would not be attending his rostered shifts. A medical certificate was provided by Dr Farahmand and Mr Byrne did not attend work on the nominated days. On the employee’s return to work disciplinary procedures were commenced and ultimately Mr Power, the newly appointed Mine Manager dismissed Mr Byrne on 12 May 2014 by letter.
The appellant claimed the dismissal was for an adverse reason because he had engaged in industrial negotiations and he had taken leave because he was sick.
In evidence which was accepted by the primary Judge it was found that Mr Byrne’s medical certificate was genuine, because he had an exacerbation of asthma and a lower respiratory track infection.
The primary Judge also accepted the reason Mr Power provided for the dismissal, because it was in reliance of what Mr Lawn had told him about the conversation on 22 April 2014, namely that Mr Lawn had been threatened with a medical certificate if Mr Byrne did not get his annual leave, despite the processes for such leave and the impact on production and other employees. Mr Lawn considered that Mr Byrne was conducting himself in a dishonest manner because he appeared well to him. The primary Judge believed Mr Power that he did not believe Mr Byrne was unwell or that any significance should have been placed on the medical certificate because in Mr Power’s experience they were easy to obtain and based on self-reporting.
The Full Court of the Federal Court dismissed Mr Byrne’s appeal, with Justice Buchanan dissenting.
In so doing Justices Jessup and Rangiah relied heavily on the finding by the primary Judge that the decision maker Mr Power did not believe Mr Byrne was sick and that there was clear evidence to support that finding and the colliery belief the employee was being dishonest. In so doing the dismissal did not fall into the category that it was a prohibited reason. This was not altered by it subsequently transpiring Mr Byrne was medically unwell.
 The circumstances referred to by the appellants in their outline might well have been the stuff of the cross-examination of a decisionmaker in a case such as the present, and they may well have contributed to an outcome adverse to him or her. In the present case, however, they did not. It was for her Honour to weigh those circumstances in the balance against the evidence which favoured the conclusion for which the respondent contended. A crucial finding by her Honour, in my view, was that Mr Power did not believe that Mr Byrne was sick at all. To the extent that inferential reasoning might have had any part to play in her Honour’s path to the making of that finding, it could only have supported it. The conversation which Mr Byrne had with Mr Lawn on 22 April 2014 was foundational. It provided the plainest of justifications for the belief to which Mr Power swore. There was no circumstantial evidence to which our attention was drawn on appeal that would undermine her Honour’s finding in that regard. By definition, neither Dr Farahmand’s certificate nor her Honour’s own finding that Mr Byrne had been sick would do so. The simple fact was that Mr Power said that he believed neither Mr Byrne nor Dr Farahmand, and her Honour accepted that he was telling the truth in this regard. Once that bar was crossed, the conclusion that Mr Byrne’s absence on account of illness was not a reason why he was dismissed by Mr Power followed almost as a matter of course. It was not “glaringly improbable” or “contrary to compelling inferences”: if anything, the contrary.
Justice Rangiah agreed:
 The issue is whether that distinction is a valid one in circumstances where it is evident that but for Mr Byrne taking sick leave, he would not have been dismissed.
The focus of the enquiry as to whether s 346(b) has been contravened is upon the reasons for [the employer] taking the adverse action. This is evident from the word “because” in s 346, and from the terms of s 361. The enquiry involves a search for the reasoning actually employed by [the employer]. The determination to be made by the court is one of fact, taking account of all the facts and circumstances of the case and available inferences.
 More particularly, in Board of Bendigo Regional Institute of Technical and Further Education v Barclay  HCA 32; (2012) 248 CLR 500, Gummow and Hayne JJ noted that the enquiry is whether a proscribed reason was a “substantial and operative” or “operative or immediate” reason for the adverse action. Their Honours said:
 …The phrase “operative or immediate reason” used in [Maritime Union of Australia v CSL Australia Pty Ltd  FCA 513; (2002) 113 IR 326] is relevantly indistinguishable from the phrase “a substantial and operative factor” used by Mason J in [General Motors-Holden’s Pty Ltd v Bowling (1976) 136 CLR 676].
 …An employer contravenes s 346 if it can be said that engagement by the employee in an industrial activity comprised “a substantial and operative” reason, or reasons including the reason, for the employer’s action and that this action constitutes an “adverse action” within the meaning of s 342.
 In BHP Coal, Gageler J drew together the threads of Barclay. His Honour described the enquiry as being directed to “the operative and immediate reason” for the adverse action. His Honour said:
 Analysis in the appeal to this Court must begin, as analysis began at each stage of the proceedings in the Federal Court, with consideration of this Court’s decision in Board of Bendigo Regional Institute of Technical and Further Education v Barclay [No 1]. The unanimous holding in that case was that, read in the context of ss 360 and 361 of the Act and of its legislative history, the word “because” in s 346 of the Act connotes the existence of a particular reason as an operative and immediate reason for taking adverse action. Where the adverse action taken is in consequence of a decision made by a responsible individual within a corporation, the existence or non-existence of a particular reason as an operative and immediate reason for taking that adverse action turns on an inquiry into the mental processes of that individual.
 As it turned out, Mr Power’s belief that Mr Byrne had acted dishonestly by taking sick leave was wrong. The primary judge found that Mr Byrne was genuinely sick. However, the question of what the employer’s reasons for dismissing Mr Byrne were must be considered on the basis of what the employer knew or believed at the time of the dismissal. The primary judge found that the decision-maker genuinely, although wrongly, believed that Mr Byrne had acted dishonestly. That belief was brought about by Mr Byrne’s conduct. The fact that it was demonstrated at the trial that Mr Byrne was in fact genuinely sick and entitled to take sick leave could not be determinative of the employer’s reasons for dismissing him at an earlier time.
The appellant also argued that the primary Judge was in error because the employer did not discharge their burden of proof by not calling other human resource personnel at the mine to give evidence. Both Justices Jessup and Rangiah were unpersuaded by this because the primary Judge believed Mr Power and it was open to do so on the evidence. It was rejected that section 361 of the FWA imposed an obligation to call persons who might have influenced the decision maker.
 Notwithstanding that relatively minor reservation, I am unpersuaded by the appellants’ case on appeal that her Honour’s conclusion as to Mr Power’s reasons was attended by error. While a party’s failure to lead particular evidence may tip the scales in favour of drawing an inference adverse to that party, the inference must still be fairly open on the evidence which has been called. In the present controversy, the questions presumptively in play were, first, whether the uncalled witnesses had advised Mr Power to dismiss Mr Byrne, and secondly, whether he followed that advice. At the first level, her Honour’s observation that the advice given by the three human resources staff members who did not give evidence related to matters of procedure has not been challenged. At the second level, Mr Power gave evidence, was tested on his reasons, and was believed by the trier of fact.
 Although not specifically adverted to as a factor by the primary Judge, I think the circumstance that the participation of each of the three uncalled human resources staff members was limited to attendance at meetings at which others were present, either without or additionally to Mr Power, was also relevant to her Honour’s conclusion that no adverse inference should be drawn from the respondent’s omission to call them. Put the other way round, there was never an occasion when one or more of those staff members met with Mr Power in the absence of some who was called to give evidence. In respect of every occasion when Mr Power’s thinking was potentially exposed to the influence of others, at least one of those others was called as a witness.
 Once the notion that, by the operation of s 361 of the FW Act, the respondent was under an obligation to call every person who might have influenced Mr Power in some way is rejected, there was nothing about the evidence, or the case generally, to justify the conclusion that the respondent ought to have called these three human resource staff members as an indispensable component of its evidentiary case. There was, correspondingly, no error in the primary Judge deciding the case by reference to the evidence which was called.
David Cormack – Brisbane Barrister & Mediator