"Does your nose grow if you lie?" the son Pinocchio asked his father Gepetto in a play I recently (Real Boy, by Matthew Minniciano) Gepetto was quick with his answer. No that doesn't happen to me, because I am human. It only happens to you because that's how I made you. That logic is often heralded by some of the best liars of our times... No they are not lying, and if you call them on a lie, they You are Lying.
Their sense of infallibility if profound and does not have to backed up with evidence.