David was a machine operator in a cheese factory. After confiding in a colleague that he had had a brief affair with his supervisor's ex-wife, several co-workers began picking on him by making negative comments. This lasted over two years. Despite numerous complaints to his supervisor, who witnessed some of these insults, nothing was done. Despite the employer's zero-tolerance harassment policy, when the employer's HR department became aware of David's allegations, it launched only a superficial investigation: it did not ask who the perpetrators were or gather facts about the specific allegations. It accepted the supervisor's view that it was not a serious problem. After his lawyer's offer to the employer to meet to discuss the matter further was rejected, David filed a lawsuit alleging constructive dismissal, based on the employer's failure to provide a harassment-free environment. The court agreed, finding that in light of both the nature of the comments made and the length of time they continued, it was reasonable for David to leave his job. It awarded him 12 months' notice (a year's worth of compensation).

Question -

What lessons does this case hold for emplovers?