I studied "anger management" - a much derided, much misunderstood field. The bit where the angry person stops looking at the target is the moment things get dangerous - because they know, that looking at the (subject) will tip them over the edge, but also looking at (the subject) means they have to see them as a person.... In short, not good - and any time you find a pub fight and the protagonist isn't looking at you any more - WALK AWAY. FAST.