BigWilliam - Cross facing is fine, cross facing so hard you break someone's nose is an asshole move.
Yup. 
Snap his arm next time you get it. That or blood choke him straight out. If he gives you 150%, either give it back or don't roll with the guy. I would go with not rolling with him.
Listen to Rush -vegard - do you crossface from the back? not that I know of.
sounds like he put the baret yoshida on you and can-openered your nose. definitely not part of training.
what did he do after he broke your nose?
If he didn't apologize profusely, you should wait outside in the dark with a baseball bat.Totally this
Yeh, basically this. I crossface people doing bjj but if he broke your nose he must have been a total dick.
We do not train to be merciful here. Mercy is for the weak. Here, in the streets, in competition. A man confronts you, he is the enemy. An enemy deserves no mercy
BigWilliam - Cross facing is fine, cross facing so hard you break someone's nose is an asshole move.+1