It's a can-of-worms discussion, since everybody would have their own interpretation of the semantics, but, IMHO, anytime a person is attacked by using a stereotype about his/her race, that is racism. The race in question doesn't matter. Saying in effect (to paraphrase him), "Get your slow white asses out of here," or "...getting beat in basketball by a bunch of Opie Taylors," implies that being white is inherently unathletic and/or slow. It also could be construed as an insult to African Americans, in that there is an implication that if you're black you must be a great athlete. Obviously, that in and of itself is not an insult, but, it does perpetuate a stereotype that many would find offensive (much like if you are Asian, well, you must be good with computers, etc.).
That said, count me in the category that feels our culture has become waaaay too sensitive, and I'm firmly of the belief that the PC stuff has gotten out of control. I don't hold any ill-will towards him at all, but, it does need to be called out for what it is, and, that being an emotional fan is not an excuse.