Here are my thoughts on how to handle situations like this:
- Do not roll back the roll back. That is just starting an edit war and will lead you nowhere.
- You can leave a comment (as I did) and try to explain. If you do, do it as politely as possible. Someone else using a bad tone is not an excuse for you to do the same. If you do not feel that you have the energy to be polite and clearly exaplain the issue, then do not leave a comment at all.
- You can absolutely flag for moderator attention. A lot of situations are borderline if they warrant action or not. In those I usually flag, and let the moderators draw the border. You can look at your flag history and see if your flag was rejected. Unless you have lots of rejected flags I would not worrie about disturbing moderators with unnececary flags.
Personally I would not both comment and flag as that just adds to many voices. Instead I would pick one based on how severe I think the case is. In this case I commented and did not flag, but given the developments following your flag I think flagging would actually have been a better decision.
Thats my two cents, not sure if they are in line with what others think. Anyway, thanks for taking the time to try to figure out how to handle these situations in a good way!