Well I think it can definitely be a reflexive response by someone who just doesn't like being contradicted, but it could also be a feeling of "you aren't trying to understand what I'm saying, you're just trying to think of a way to counter it". So it could be worth taking a moment to back up and taking a deeper look at what the person is trying to say.

I have a really annoying way of understanding things. I piece shit together bit by bit and guess at the answer before I'm told. It comes off very interrogative. Even when I'm wrong my attempts to understand seem like I'm being antagonistic. I try to explain to some people how I'm trying to fix the underlying assumptions that led me wrong.

Some people won't respond well and it's really difficult for me to accept that there isn't a way to mediate both of us being happy.

Ask yourself why you feel the need to get the last word, or be right? Ask yourself how important a topic is and gauge your audience, do they really need to hear about what your going to say for the next few minutes? Many times something that is said was never said with the forethought that a response would even happen.

Often times people are having emotional conversations, not factual conversations, it can be hard to tell the difference.

You learn the most when your mouth is not moving.