Dunlop Mixing and Technical Services (Pty) Ltd v Numsa obo Nganezi (D345/14)  ZALCD 9 ;  10 BLLR 1024; (2016) ILJ 2065;  JOL 35924 (11 May 2016) per Gush J.
The Labour Court reviewed and set aside an award of reinstatement in favour of a number of employees who were dismissed for valid and fair reasons relating to their violent conduct during a protected strike but related to derivative misconduct. The Labour Court stated that employers are entitled to expect orderly conduct during any strike and that employees owe a duty of good faith to employers.
Excerpts with edited footnotes and links
 In FAWU v ABI  12 BLLR 25; (1994) 15 ILJ 1057 (LAC) the Labour Appeal Court held the following:
In argument before us it was accepted by the appellants’ counsel that if it was found that each of the appellants had associated themselves with the assault in one or other of the forms alleged by the respondent, the dismissal was justified.
It was submitted by the appellant’s counsel that the onus of establishing this was upon the respondent, and that the onus was to be discharged as a matter of probability. I have assumed for purposes of this appeal that that submission is correct.
There was no direct evidence linking any of the appellants to any particular act in relation to the assault, and the respondent’s case was based on inference alone. None of the appellants gave evidence, either in the court a quo or in the course of the disciplinary hearing. The attitude adopted by the appellants throughout was that it was for the respondent to establish their complicity, and that no case had been made out against any of them which called for a reply.
The extent to which a party’s failure to give evidence may properly give rise to an inference against him has received considerable attention from the courts. What emerges from the decided cases is that his failure to do so cannot by itself constitute proof of what is alleged against him. Nevertheless the evidence against him, though not conclusive, may be such that an explanation would be expected if one was available. In such cases his failure to provide an explanation may be placed in the balance against him.
In the field of industrial relations, it may be that policy considerations require more of an employee than that he merely remain passive in circumstances like the present, and that his failure to assist in an investigation of this sort may in itself justify disciplinary action. [pages 1062-1063 of the ILJ report]
 More recently the issue of derivative misconduct was considered by the Labour Appeal Court in the matter of Western Platinum Refinery Ltd v Hlebela & Others  9 BLLR 940; (2015) 36 ILJ 2280 (LAC) where the Honourable Judge of Appeal Sutherland, after considering the judgment in Chauke & Others v Lee Service Centre t/a Leeson Motors (1998) 19 ILJ 1441 (LAC) stated the following:
The effect of these dicta is to elucidate the principle that an employee bound implicitly by a duty of good faith towards the employer breaches that duty by remaining silent about knowledge possessed by the employee regarding the business interests of the employer being improperly undermined. And controversially, and on general principle, a breach of the duty of good faith can justify dismissal. Nondisclosure of knowledge relevant to misconduct committed by fellow employees is an instance of a breach of the duty of good faith. Importantly the critical point made by both FAWU and Leeson Motors is that a dismissal of an employee is derivatively justified in relation to the primary misconduct committed by unknown others, where an employee, innocent of actual perpetration of misconduct, consciously chooses not to disclose information known to that employee pertinent to the wrongdoing.
 The third respondent held that an employer that relies on derivative misconduct is obliged to prove on a balance of probabilities that the employees knew or must have known about the principle misconduct and did not disclose it. The issue is whether on the evidence the inference can be drawn that the employees in this matter were present.
 The third respondent in referring to the respondent employees who were not identified as being present indicates that he took into account that it was “possible they did not testify in order to implicating themselves” and “in my view however equally possible that they did not testify because they were of the view that the respondent had not made out a case for them to meet”. The third respondent simply concluded that “in the circumstances respondents failed to prove on a balance of probabilities that the applicants falling into this group of applicants committed misconduct.”
 By failing to consider whether or not the applicants evidence created inference that the respondent employees were present or under an obligation to exonerate themselves the third respondent does not consider whether the failure to give evidence or provide an explanation was acceptable or whether such conduct constituted derivative misconduct.