Double Standard?

Don Imus got fired and public scrutinty over calling the Rutgers basketball team "nappy headed hos". He was labeled a racist, bigot, ect ect. But Rev. Al Sharpton has admitted to using the "n" word and offensive slurs had nothing happen to him. He admitted to calling the former New York Mayor David Dinkin a "n----r ". He was not publically denounced nor was he labeled a racist. Why? Because he is black and it's ok for black people to say certain words but not white people? The Rev. himself says that it's unfair to compare the two incidents, he claimed that because Imus was on radio that it had more of an impact. But the effect is still the same-people were hurt and reputations were damaged so why isnt Sharpton being publically denounced and fire?