Oh I don't know if they got lower thresholds! First, they can be more easily sued when they're professionals. Second, they let out steam in the gym every day. Third, being around that kind of environment, there must be a lot of talk and advice over the years on how to control your aggression. So I think, because by definition they are more 'intelligently aggressive' than us, we're much more liable to do something stupid in that arena!