in an interview with Leo fong he says that someone named David Chan caused the fight. It was nothing to do with teaching westerners. This guy Chan went up to Bruce saying that Wong was badmouthing Bruce. He was doing the same to WJM - saying that Bruce was saying bad things about him. In the end Bruce said get the bastard here and we'll have it out. This is the story behind the fight from Leo Fong. Hear Leo talk about it here :-
Other interviews at the site include Joe Lewis, Wally Jay, Ed Hart, Taky Kimura.