If it doesnt concern them then why let them see the post? People will comment when they want. It wasnt entirely the commentors fault here. Sure, it was a rude comment, but i dont agree with you about the joke part. I make jokes like that a lot and i never mean them.
If you let everyone see your posts, you are asking for trouble. Its like screaming something out in public and complaining when someone tells you to shut up.
Im not on the other guys side, but i think youre giving him too much of the blame.