If Karen is talking over Joan in meetings, she should stop. It's disrespectful. I know, I've done it and I've had it done to me. The racial dynamics that Joan sees that Karen does not is indeed the problem. Any injury perpetrated on a black person from a white person is also considered racial slight, regardless of whether it's intentional or not. (i.e. a micro aggression) An injury perpetrated on a white person from a black person will likely be seen without a racial lens. This puts all white people at a disadvantage with regards to moral equivalence.