evolutionary psychology tells us humans are notoriously bad liars

Does it?

Hard to answer. Compared to what exactly? We do know that we have all sorts of microexpressions that reveal our emotional state and that most people give off indications that they are being deceptive. And this isn't just failing to hide dishonestly - there is a whole part of the brain in there actively making muscles move to give indications to others that include telling them we're lying. So whether or not we are good liars I don't know but we are certainly worse liars than we could be if we weren't actively shooting ourselves in the foot!