Play nutural.
As in, dont do anything, just ingnore, unless he does somghitn intelligent or stupid. I will always give advice first if i see a unnamed player who is completely helpless. If they play mime on me (as in, dont respond), and continue to be idiotic, i will then proceed to deservingly flame them. If everyone is yelling at him to get a reality check and its still not getting through (as in, he isnt actually playing the game at this point, he is just messing around and mabey accidentally screwing the team over whilst he does this), then I VK.