I don't buy the argument that if you use or ever have used a racial epithet that you are a racist and are just showing your "true feelings". In this case, it's more than one epithet, but it is entirely plausible that the guy went for the jugular, using the most hateful language that he could think of, to attack the hecklers in a fit of rage. If the guy were racist, I think somebody would have picked that up somewhere along the line in his career.