I hate to be the voice of dissent hear but here is my two cents worth:
I disagree, if somebody receives unwanted feedback from a member after being asked to back off, call it clash of personalities if you may, then that person should just back off and leave well alone, not continue to enflame the issue, or issues.
to continue to do so after being asked to stop is not caring, because in no way can it be construed in any other way than harassment, how is that caring? when it causes more anguish than relief?.

it will only lead to less people posting, and ultimately leaving the site as they feel they cant share what is going on with them without the perceived fear of attack by that person. Be it in the forums or on PM, I know you can put the person on ignore on PM maybe the same system should be in place in the forums as well.