Junior workers at the Greggs production unit in Newcastle, Solomon Kahsay, Yonas Tesfamariam and Robeil Araya, were unhappy with how their manager was dealing with their allegations of racial abuse.
They raised concerns after being investigated in June 2021 over accusations they took unauthorised breaks during work and falsified their attendance records.
A site supervisor emailed the manager to tell him the employees were unhappy with how he was managing the investigation and that they wanted to pursue allegations of racial discrimination.
The manager was on a day off, but came into work and said: "If you take this further you will be in big trouble", the tribunal heard.
All three men were sacked in July 2021 over the unauthorised breaks and allegations of race discrimination were not investigated.
Kahasay won a claim of race harassment, while all three workers' claims of unfair dismissal were upheld.
The tribunal ruled Greggs’ internal investigation did not probe events fairly.
Claire Brook, employment law partner at Aaron & Partners, said this case highlights the importance of ensuring managers are able to maintain appropriate behaviour.
Speaking to HR magazine, she said: “Managers should maintain appropriate respectful behaviours, even during pressurised situations. The behaviour found to have taken place in this case was described to be ‘reprehensible’."
Brook also emphasised that internal investigations must be conducted by well-trained managers, or can potentially become a legal risk.
She added: “Managers who are tasked with handling investigations and responding to complaints should be suitably trained to conduct these processes fairly, understand and adopt suitable questioning techniques and have refresher training on equality and dignity at work.”
Greggs declined to comment.