Besides using reverse racism, your co-worker was a technique I like to call "not giving you the benefit of the doubt".People sure like to bat the word "racist" around. Differences between cultures doesn't indicate racism. It indicates differing individual tastes. Believing your race is superior in all forms to all other races is racism. The rest is just good ole bigotry. Nothing wrong with that......some great comedy comes out of bigotry. I myself have come up with some awesomely bigoted statements in the name of teh funny. It's just very pathetic that many people will throw that "r" word out there so cavalier without actually considering the implications of what they are saying.
Instead of giving you the benefit of the doubt by accepting that you like hockey more than basketball, he assumed that you were racist anyway, and you just had a BS excuse handy, rather than admit you hate blacks and black-dominated sports.
I've seen it before, it is pretty ridiculous. It immediately puts the other person on the defensive, because not only do you need to defend your real reason, you also have to explain how you are not racist, which is sometimes not so easy to do.
Now, I would probably cut to the chase, and say something like, "This is the 21st Century, you should probably drop the slave mentality."