If the Rav has expressed his regret to you, it would seem that it is your cheshbon to be ????? the Rav about what he did to your friend.
If you know that the Rav has not expressed his regret and asked your friend for forgiveness, perhaps you should find a way to remind the Rav that ?????? ???? ??? ????? ??? ??? ???????? ???? ?? ????? ?? ????.
Of course, this is a very sensitive thing that must be done with great wisdom.
It would be a great favor for the Rav, and would also help your friend heal.