I don't think there is as much troll in him as you think. Without question he meets the standard definition, namely someone looking for a reaction, but I think with Castle the motivation isn't what you think it is. For him I think it is motivated by desperation and lonliness, rather than just doing it for kicks. He craves the attention because he doesn't have have anywhere else to get it from The reasons for that could be many. He may not have been in a happy relationsop with the mother of his child. He may not have had a positive upbringing. Who knows? But there is, notwithstanding, a very needing side to his that screams low confidence. As for ignoring him, that's pretty much what I do most of the time. I only engage him when I sniff a meltdown on the horizon.
He'll find a way to spin this as a personal victory, and one to be proud of. Just wait and see. I'm sure he'll claim that "Someone needed to test Anc's resolve in such a situation, goddamn it, and none of the rest of you whimpering little girls had the stones to do what needed to be done", or some such bullshit.