Many companies tend to focus on employee training, overlooking supervisor training. But even though it tends to be more expensive and time-consuming, supervisor training is an important precaution to take in risk mitigation. Training is not legally required, but would effectively allow supervisors to understand when employees are being subject to unfair treatment and ensure consistency and fairness in the workplace. For issues of termination, wage conditions, and relations with the NLRB, supervisors can minimize company liability if they understand the conditions behind company policy. Especially in cases of discrimination, supervisors are often in the best position to put an end to harassment. Taking proper action helps to avoid legal problems later.
See "How supervisor training plays a critical role in risk mitigation", Michael Henckel, The Business Journals, June 14, 2017