I would say that it is negative ad hominem. The comments are not topical, they are meta narrative, conversations about the conversation, with the intent of terminating the conversation. Most of it is ad hominem, talking about the man instead of the topic.
Often trolls will post extreme stuff which they don't really believe, or they will make unsubstantiated charges or allegations against someone, only to force them to deny it to protect their reputation.
Simply expressing a different POV, or expanding the range of the topic are not trolling.
When Dougster was trolling someone, I often posted completely off topic stuff, simply to discourage him. That is a kind of trolling, but it was trolling to discourage trolling. It was never negative meta-narrative and never ad hominem. It was always neutral subject matter.
Generally trolling is not good, because once one person does it, that encourages others.
SJG


It's ok sjg. I got that troll on ignore.