In my experience this is rarely the case.

It's much more likely you're misunderstanding their position or missing some undisclosed nuance. Often I find this just comes down to most people lacking the vocabulary or ability to refine their positions consicely enough to form coherent and non contradictory positions.

If you take the time to work through their contrictory statements with them you'll likely find there was no contradiction in their mind, instead, there was just some nuance that got lost in translation.