Thankfully I haven't run into this as of yet on DF, but if I do, I'll be pretty sure to do two things:

Send messages to the others in the group asking if they would like to try this with someone else.
Leave instance and add them to friends list and attempt a second run with someone who is capable of playing the game without that type of attitude/language.

Hell, I don't care. I'll be the first to leave and take the penalties. It'll be better then sitting around and listening to someone that I refuse to have any time for. Oh, and if I remember I'll be sure to screen shot it so that I can post it somewhere so that the problem can get handled, name unblocked.