I have never expressed anger verbally with my T but have let him have it in emails. He always answers calmly and tells me the reason for my anger, which sometimes gets me even more pissed off, or, most of the time, calms me down.

Interesting question, though. Think I'll ask him next time I see him what he'd do if I started to yell at him in session! Probably wouldn't faze him in the least, knowing him!
I've been seeing him for six years, have tried his patience majorly on MANY occasions and he's never lost it yet.