Important info: 3 mechanics in a out door bay shop. (Only a roof so any one can walk up) 

This is what heppend: a female walks up to one mechanic whos a black guy and he starts flirting for a while. I over hear my co worker say "I cant say the N word but he can be with a white woman??" This guy would often tell storys of how manny people he would try to fight aswell. So I thought he was a tough guy. I turn around and and say " shut up". He says "No! I cant say the N word that aint" So I angrily approached him and said "Shut the fuck up!" He stepped back and says "oh every one has to be a gangster" I start saying every thing i could to get him to fight me. The manager comes out and the guy I thought was so tough and readily looking for a fight runs behind the manager. I then got sent home for a day. Came back the next day every thing was fine but the tough guy called out for the day then called later that day and quit. AITA?