For me, it is situational. It depends on what the "offense" is.

There are people in this industry that I refuse to work with, and have turned down very large accounts with, because of one thing or another.

For most aspects in this business, there are plenty of contracts and traffic to go around and there are too many people in the industry that i know well and feel comfortable with to waste my time with someone who is untrustworthy, etc. Reputation is very important in this business, and I pay close attention to it.