Unless it was severe we wouldnt ban first thing. We'd give the offending party a time out for a day to think about. That person would be notified about what was happening and why. We felt a 24 hour cooling off period was good for keeping things from getting further out of hand.
Permabans are pretty rare around here, too, except in egregious cases. Most of the time, just stepping in and asking people to calm down does the trick, but not always.