I won't red-flag anyone based on your observations.
The evidence isn't compelling enough to do that, in my opinion. It also could have been a sophisticated attack on that particular user/group.
I guess it's fair to add a few (more than a few) users to my ignore list.
The account I mentioned has already received two negative tags. So, I think he will not go too far with this account. But I think he was trying to figure out how to earn some merits. He has been on the forum for a while. He could have been ranked as a Hero Member by now if they could contribute to the forum. But he spends their time doing useless bounty hunting.
Probably, he figured out that it is possible to earn some money from signature campaigns if he can rank up his account. So he was trying to get some merit from you.
By the looks of it, this guy probably never visited any of the global or local boards, or read the rules at least once. If he had he would have never dared to ask for merits in the first place! He just did nonstop bounties and bunties!
An average person knows well enough that asking merits would paint them red all over!