Some human irrationality seems adaptive. Humans apparently deceive themselves so they can manipulate others without actually lying - so as to avoid detection.

That does not directly contradict Omohundro. The quotation merely suggests that almost-rational humans will seek to self-modify in the direction of becoming less self-deceptive and better at lying. A look at the self-help literature tends to confirm Omohundro's prediction.

Are the liars going to win, though? Nature subsidises both transparency and lie detectors, for reasons to do with promoting cooperation. In the future it may get even harder to convince others of things you don't personally believe - as is dramatically portrayed in The Truth Machine.