It may be hard to figure out if somebody is nitpicking on irrelevant stuff as "pointing out fallacies" because they are sure about their conclusion and just wan

It may be hard to figure out if somebody is nitpicking on irrelevant stuff as "pointing out fallacies" because they are sure about their conclusion and just want to barge their way through to it. When you're dealing with someone like that, there's very little incentive to continue arguing, they will latch onto whatever it is that makes them feel they were right without actually consider the issue at hand. It may actually be used as a test of their desire to engage with the problem. Throw them an irrelevant thing they can be right about (maybe even a typo or wrong grammar), and see the actual issue fade away from their mind.