What's the difference? There is NO difference, however there is a difference on who gets attacked and who gets protected.
Azealia gets GLAAD and others hounding after her, Dan... no one. Now before anyone tries to say that Dan used it differently, please remember that a slur is a slur; you can't pretty it up. If it's shit, it's shit regardless if you Fabrezed it and put a pink bow on it.
I'm not defending Azealia here, I'm just pointing out the bias and privilege besetting this entire mess. If she gets called out, then keep it consistent and call out everybody else.