Shouting THATS NOT TRUE has never invalidated evidence . <| sep |> As the other comment said , polygraphs are literally pseudoscience , and should never be used as evidence for anything . They ' re no more effective than a coin flip of lying or not lying . The only thing they are good for is to pressure people into telling the truth after being told they failed and the police now know the truth . However , you could also get the same effect by telling the suspect that someone else told them the truth , or they ' ve been seen on camera or something . <| sep |> Now , it was my turn to stare at her . The drink was indeed for offer for $ 5 the Tuesday of that week , but the offer was only available through ordering on the app , and , more importantly , the current situation was occurring . on a FRIDAY . Yeah . as a former student mixing up days was not uncommon . I sat through a 2 hour lecture on poetry from the 16 th century because I went to my lecture on a Monday instead of a Tuesday