It really looked a lot like a Nazi salute. And he did it twice. A non-troll would afterwards say ‘oops!’, my bad, I didn’t realize in the moment what that looked like.’ Instead, he just joked and claimed he’s a victim of people calling others fascist too easily. He either did it on purpose as an inappropriate joke, did it on accident and is too blind to realize it was a mistake, or did it on purpose because he’s an actual Nazi. My guess is the first one, with the second one being the next most likely…I hope it wasn’t the last one.