huh. well, bias happens every day in work, conscious or not. friends, people you don't like, people that you don't know.......and conflicts happen. And imagine all the second guessing from others on every move about Joe (including, most importantly, the rest of the team). It isn't just how they act, but how everyone else thinks they are acting. This is super, super, common in business, to have issues with how teams perceive a manager treats another team member, imagine how it would be with a relative. I mean, this is management 101 stuff that you have to think about every day with a team.