If a person caused embarrassment to his friend in-front of other people, not by saying hurtful words but for example by bringing up a topic which causes his friend embarrassment is he required to ask forgiveness from his friend? And does it make a difference if he can assume that his friend probably doesn’t have hakpada on him? If he does need to ask forgiveness, is it enough to ask for forgiveness in private or is he obligated to ask forgiveness in-front of the group who were present at the time of the embarrassment?
If he caused his friend embarrassment he should ask him forgiveness, but in your case he wouldn’t have to ask it in public. If you are confident that he doesn’t have a hakpada, then you are assuming that he was already mochel it.