Stupidity: At the end, the police inspector talks Bruce Lee into surrendering, and about 8 people (including the inspector) escort him out of the school. As soon as they're outside, Bruce sees a formation of heavily-armed police preparing to fire. Realizing he was betrayed, Bruce Lee charges, screaming, straight into a barrage of gunfire as the action freezes for credits. However, before the action freezes, there's NO reaction from anyone standing behind Bruce Lee, even though they are directly in the line of fire. Even the police inspector (who knew the police gunmen were waiting outside) just stands there instead of immediately diving for cover.
Stupidity: While awaiting their flight home, Nancy told Teri, "Think I miscalculated the tea. I'm not gonna last three-and-a-half hours [on the non-stop flight with no restroom facility]." Nancy then went into the gift shop where Stuart Couch introduced himself, asked if he could get her a drink, and bought her a bottle of beer. Nancy drank at least some of the beer on screen, even though she was already concerned about drinking tea before her flight. (00:59:28 - 01:00:30)
Stupidity: The first time they go into Butler's garage next to the prison they are breaking in, but Butler never witnessed any break in clues to raise his suspicion. They replaced the lock with the exact same lock. It is clear that they didn't know that this was his access point to the prison, but once they found out there is no way to cover up that someone compromised the facility. How is Gerald sure that the bomb will remain under the meeting room while on his way back to the cell? He has a camera in the meeting room but in the bomb room he didn't bother to put one.
Stupidity: Anyone with a job in the White House would have to be known to the Secret Service on a daily basis, so the two Secret Service agents that find Cory the janitor should have been aware of his identity without him having to state who he was and that he worked there.
Stupidity: When Laura goes back to the house to get her bag, she takes off her wedding ring and flushes it. Problem is, she knows how her husband is and doesn't take the time to make sure the ring goes down! But she makes sure there's no other trace of her being there (flushing her hair down the toilet and drying the floor off from her wet feet!).
Stupidity: When the thunder/lightning starts, Hannah correctly tells Connor "We gotta get downhill." Then she tells him to run and stop, plus shows him to crouch down. Granted, they needed to act fast, but her instructions were poor for someone supposed to be trained in safety. Crouching should not entail placing one leg from the knee down onto the ground - only the balls of the feet should touch the ground and the heels should be together. She didn't tell him NOT to lie down, but he was when he fell. (00:53:14)
Stupidity: In the exciting denouement when the SS company approach the ostensibly disabled Sherman, the SS would have just walked around it. A burning tank was a common occurrence. I doubt they would start climbing on it and they certainly wouldn't start charging at it individually as to get mowed down. The SS were well trained units. Such stupidity is unlikely.
Stupidity: When questioning the heavyset witness after his having seen Costner in the hallway, there is no mention of the most obvious identifiable feature...the pearly white Navy uniform he was wearing. Instead, Costner is described as being a common "everyman."
Stupidity: The chef/cook of the house has his rifle, and he knows Morgan lost control and pretty much killed everybody on the premises. He comes face to face with her, but he lowers his rifle instead of taking the subject (Morgan) out with a shot. There is no logic here but to only pro-long the film. There's no reasoning with a scientifically created subject which is killing everybody it comes into contact with. (01:09:00)
Stupidity: There is a scene in which the phone rings back at the house and Andy goes to answer it. None of the henchman respond immediately, but instead WAIT for him to almost answer the phone before becoming making a move. You would think they would yell at him to not answer it or have one of them rush to guard the phone the moment it rings. Obviously the entire scene was done this way for the sole purpose of suspense.
Stupidity: The metro police officer (and co-conspirator) went to the old cement factory where the other bank robbers were. Since the police officer (accomplice) wanted the money and did not want other police officers to be nearby, he called 911 and made an anonymous false report stating he spotted the person police were looking for and misdirected them further away. Maybe a good idea, but he made this call using his own cell phone. (01:12:20)
Stupidity: At the end of the movie during the shootout. Cops would not engage in automatic gun fire with dozens of civilians in direct cross fire. Why not get a chopper and chase them down a bit maybe in an open area with fewer civilians? Then maybe engage in gunfire.
Stupidity: Why doesn't Nick just show Darian's parents or maybe even the police the 99 phone messages from her or the shrine underneath his living room? He had had enough of her at this point, and was even willing to move away at that point.
Stupidity: The marble somehow got under Don's skin at the bottom of his leg and was moving up the length of his body. Instead of heading off the marble in order to intercept and stop it from continuing up his leg, Don got a knife/box cutter and jabbed it into his skin near the bottom of his leg and trailed the marble, causing a long gash that served no purpose (other than creating a lot of blood and making a gory scene). The marble eventually exited his body via his eye. (01:04:40)
Stupidity: There is a scene about a null hypothesis proving Cassius is the killer. Nearly everything is wrong in this scene. Statistically, you never prove a null hypothesis true. (01:23:11 - 01:24:22)