If a person sees the error in a certain belief or says something unpopular, steps forward to admit they're wrong and apologizes, I see nothing wrong with just letting it go. Of course, it''s also not unreasonable to require a certain period of time to allow the 'offender' to rebuild trust through future actions and words.
So someone who starts a discussion that is unpopular, just to have a discussion, who asks why something might be a bad idea, is an "offender"? Guess I didn't get the memo that discussion is verboten.