I don't see the problem, but since I'm not black and don't have the connection with black community other than through the Internet, I can't really understand why there are fumes when someone drops the N-word. for me it is just a fun word that I've seen in use only when causing no harm to anybody and just for giggles, still I never use the word, cause English is not my first language and I have no one with whom I could use it.
so if the apology was needed
edit: I've made some research and I see where it comes from.