I don't mind the perma-karma system at all,
I only fire my weapon as inno if I am 100% certain someone's a traitor.
(Like if theres 3 people left, Me, a guy who killed a T, and someone else, you obviously know by process of elimination the last person's a T.)
But still, if you happen to fuck up, you should be given the chance to raise your karma, like, oh, I don't know, GAINING KARMA FOR KILLS AS A TRAITOR.