When you feel like a friend or employee is your adversary, it's easy to forget that they, too, are doing the best they can. But you would not have a relationship with someone or hire someone you do not consider a good person. Part of building relationships, whether in your personal or work life, is trust. Assuming good intentions will make you a better manager. Instead of viewing an error as a personal failure, by giving people the benefit of the doubt, you can see more clearly individual or institutional skills, as well as knowledge gaps; without having to put them on the defensive.