I have a friend who uses sarcasm a lot. He ends up hurting people and then says, “Oh, come on! I was only kidding.” I suspect hidden and deep anger in him. What do you think?
If this is a pattern and if he sees that others are hurt (which you imply that he does), then, yes, I suspect the same: hidden (from him) and deep anger. He may need to courageously explore who has hurt him in the past and try to practice forgiving, if he chooses. It might lessen or even eliminate his hurtful sarcasm.