In a unanimous judgment, the Constitutional Court has brought certainty to the test for derivative misconduct and what an employer who wants to rely on such conduct must prove to justify dismissal. This judgment is National Union of Metalworkers of South Africa obo Khanyile Nganezi and Others v Dunlop Mixing and Technical Services (Pty) Ltd and Others  ZACC 25. The burden of proving all these requirements will not easily be met.
The concept of derivative misconduct was created by our courts to overcome difficulties when identifying all the guilty parties involved in group misconduct. Where members of a group have committed misconduct, the rest of the group would have been in close proximity without being directly involved. Whilst these bystanders may not be guilty of the group misconduct, they may be found guilty of another type of misconduct if they are unwilling to identify the guilty employees. This is derived from the breach of their duty of good faith towards their employer and is known as derivative misconduct.
The judgment deals with violence during a protected strike. Three groups of employees were dismissed: those that were positively identified as committing violence, those that were identified as present when the violence took place, but who did not participate, and those who could not be identified as being present when the violence took place. This case deals with the dismissal of the third group only.
The Constitutional Court found that in order to prove derivative misconduct, it must be the most probable inference that each of the employees
- Was present at an instance where the misconduct was committed
- Would have been able to identify those who committed the misconduct
- Would have known that their employer needed the information from them
- Failed to disclose the information to their employer
- Did not disclose the information because they knew they were guilty and not for an innocent reason.
The Court found that in instances where the employer sought to impose a duty on employees to disclose information about their fellow striking employees, the reciprocal nature of the trust relationship between them would require the employer to guarantee the safety of the disclosing employees. As this had not taken place, the employees did not have a duty to disclose information and were not guilty of derivative misconduct.
The Court did not provide any clarity on what would be a sufficient guarantee of safety. Practically, a guarantee of anonymity should suffice, but employers should give careful consideration to the disciplinary process to avoid a scenario where the disclosing employees are unnecessarily required to give evidence or where their identities can simply be deduced from the outcome of the process.