If someone told me my son stole crab legs or raped a girl (allegedly), I'd be extremely disappointed/angry. If someone told me my son screamed a joke that was trendy at the time to get a laugh, no, it wouldn't bother me. I'd just wish he was funnier than that. He was in a college dining hall, not at bingo at the local church. Kids do dumb stuff in college. I wouldn't have done it, but it doesn't bother me. I don't think that that incident shows what kind of person he is, at least with the connotation you used. It does show me that he has a big personality.
I understand people thinking he's a scumbag for a few different reasons, just not this one.