I use intuition to form initial opinions on if someone is trolling. You can't put your finger on it, but you can tell that it "seems" like trolling.
I think it works because your brain has a mental model of what it perceives, and when something does not fit the current model, then you get a "feeling" that something is not right.
Because the human brain evolved from a creature that was often a prey animal, then evolutionary it makes a lot of sense to have a lot of false positives. It's not really dangerous to imagine you hear a wolf behind you, but it is very dangerous not to hear a wolf behind you.
You should not ignore your intuition, but that does not mean you should trust it. Pay attention to it, then check out what it is telling you. Just don't use it as an authority. Lots of things "seem" wrong, but are not.