Hi bus boy,
What kind of a person stands behind wrong. Maybe my belief system is all wrong?
I don't think that you have something wrong with your values. In your case, I think it's about how she couldn't control you like she can control her current boyfriend. I wouldn't worry about him, it sounds like he has his own lessons to learn.
Three people makes a triangle, he's probably not aware that he's rescuing your ex and your ex is casting you into the role of persecutor, the same role that her bf will be cast in at some time in the future. It propagates unnecessary drama and she's blame shifting her bad behaviors on others. Be aware of triangulation and don't assume the persecutor role that she cast you in, stay in the center of the triangle, don't take sides with your ex or her bf so that you don't play into her drama. That's just my two cents.