Chris was an asshole on the show. And I say that as a person who has met him, sparred with him and thinks the world of him.. his drunken escapades were way out of line and retaliation was without question due. However Bobby Southworth went somewhere you should not go... having heard about Chris' estranged relationship with his dad he thought it would be okay to call him a "fatherless bastard". As a person with a similar relationship with my father I can tell you, you say that to me... combat training be damned on my side or yours, you're getting a blunt object to the head.
Point is, Chris acted like a douche... but Koscheck and Southworth were way out of line. Koscheck and Chris are cool now, but to my knowledge Bobby never made any attempts to right that situation, but who knows what happened when the cameras were off.
EDIT: HEY POST 2000!!! Rock N Roll!