downthestrada - I agree.
I fired a man who twisted himself in bloody knots trying deny a racist joke he made about a customer (he had previously drunkenly racially abused a member of the public whilst on company time, and was let off - not by me! - so was extra surprised when I fired him for the 'mere' joke).
If it were purely the joke, and he had held his hands up saying, 'I was an idiot. These issues don't affect me and I don't understand them. I made a stupid joke. I'm sorry'... then it probably wouldn't have gone that way.