The two situations aren't equal. It's the cultural processes in ingroup vs. outgroup dynamics. Many things that are ok between ingroup members are not ok with somebody outside the group. The frat situation is clearly racist...whereas the basketball situation is not. For example, I can call many of my friends on this forum a "redneck bastard" and we'll laugh together; but if a black stranger were to call one of those friends a "redneck bastard", it would surely lead to a fight.