His racist language while not a good thing is less racist and more dumb and locker room talk.
In an email to Washington Football Team president Bruce Allen, Gruden called the NFLPA's executive director, DeMaurice Smith, "Dumborris Smith," and said that "he had lips the size of michellin tires."
Not defending Gruden but he could have just as easily told a “your momma” joke. He was belittling the man because he thought he was an idiot not because he was black.