I think the reaction was fine, Vinny was acting like his friend and was trying to get some tips and rolled with Nog because he liked him.
Even if Vinny was on the other team Nog would help him out a bit and take him under his wing (maybe after the show it seemed)
Brazilian are very patriotic and back up each other, that shit talking Vinny did with Mir was very disrespectfull IMO. Nog seems to be someone really straight foward and serious about that kind of stuff. That justify his reaction pretty well