Fedor is a very calm guy. He has said in interviews that he does not hit anyone outside of a ring. If he is simply insulted, I am sure he would act in an adult manner and avoid throwing hands.
Fedor is human, though, and if pushed to his limits would by nature either defend himself or go on the attack if he is threatened enough.
He isn't someone like, say, Rob Emerson, who would snap someone's back in half with his index finger and thumb for insutling his Godlyness.
By the way, Welcome to the forum!