Feelings Video – What if a person really is a jerk?

I just listened to the Feelings video replay and a few questions came up while the woman who was feeling angry about her father in-law came on. I understand that her thought (my father-in-law is a jerk) is what was causing her to feel angry because thoughts create our feelings. But what if a person really is a jerk – what if someone acted in a way that really was selfish or mean spirited? Do we always have to try to be compassionate — for example, the woman who was angry said maybe she could just think that her father in law was old and forgetful and then she wouldn’t feel as angry? But what if it’s a more severe situation. How do you move past being angry? Also– how does this idea fit in with the whole thing about having a plater of feelings and feeling all of our feelings? I’m just a little confused about changing our thoughts to change our feelings VS feeling our feelings when they come up. Hope this makes sense. Thank you very much.