Stupidity: When Gaz tries to steal a jacket and Dave, who works as security, catches him in quite a dramatic manner they are seen by other employees. Dave lets Gaz go because he is a friend. But the next day both stroll together through the shop as if nothing had happened, with no enquiries or follow-up from the other employees. (00:59:30)
Stupidity: When Gail shoos Luke off the first day, in fact nobody accompanies him to the door and they discuss the evil plans when he's not even gone nor they even check he is, they just go ahead with the script. It's a rather odd dynamic, very rushed and movie logic-like. Or theater logic, since it's a typical 'exit stage left' moment.
Stupidity: Paul Manfield (Arthur Pope) and his family have been hiding from and eluding the FBI for fifteen years, but Paul gets so intoxicated one night that he loudly sings "Pretty Woman" walking toward his house - where neighbors could hear - and yells that he is not Paul, he is Arthur Pope. (00:52:18)
Suggested correction: People do seriously stupid things when they are drunk, and Manfield/Pope is very, very drunk.