Have you watched the show where they do an interview of some that spotted Sasquach? They give them polygraph and they believe the story, that they concocted so deeply they pass the test.
They are schizophrenic. That's how they lass.
I really find it hard to believe anyone still pays heed to polygraph tests. You may as well buy some random selection of $1 electronics from Ebay and connect the subject to that; it'd be about as reliable.
Have heard of some that can avoid even sodium mamatol and sodium pentathol injections.