I have seen them throw blows. They used to do it in the "grandmasters/masters lounge/area" (I.e. smoking area near tourney where students are not allowed). Now they bicker and shout at pre/post tourney meetings. I know because I have been there(the only non korean to attend in my area). I won't get into what is normally discussed as it is not part of this thread.
If I were you, I would be considering changing the people that I associate with.