Yeah I saw that one. I didn't see it as someone necessarily messing with you personally - but just a liberal biting back at a conservative post. You put Obama, so his "retort" is to put Trump. You just hit a nerve maybe.
I don't think it's really a big deal. But maybe just remember the username? If the same thing happens again repeatedly then he would be a troll I guess.
Is that similar to what you're thinking about the situation?