Stupidity: All of Robbie's circuits have been burned out as a result of Morbius ordering him to kill the Id monster. The crew only has 24 hours to get the ship loaded and a safe distance away from Altair IV before it explodes. But one or more of the crew spends the little time they have fixing Robbie, a very sophisticated piece of technology, who is working the controls at the end of the movie.
Stupidity: The crack house workers are all topless to prevent 'hiding' any product for personal use. Yet are also wearing parachute type pants that they could easily hide things in.
Stupidity: When the flying snowmobiles attack, Bond tells Elektra to go into the gully, and he'll lead them into the trees...completely ignoring the fact that these bad guys are here to kill her, so why would they follow him instead? Of course they all do. Either a plot contrivance or a blatant set up, which he doesn't remotely consider.
Stupidity: The patient was wearing a white and gray striped tie when he was walked into the ambulance. The EMT did not remove or even loosen the patient's tie (to facilitate breathing). Instead, the tie was moved from the front to along his shoulder/neck, apparently to get it out of the way while she was cutting off the patient's shirt. (00:07:50 - 00:08:20)
Stupidity: Nicholas Cage saves the kids coming out of the dark dimension exactly at midnight but gets back home at dawn. It should be noted that he has two other kids to bring back home and if we assume he did that already, it would explain part of the time discrepancy. In that case he kept his wife up all night when she was fearing for the safety of both without a word, but she's not upset or anything.
Stupidity: In the bar scene, Jack gets into a fight with a guy he busted a few years back, then Reggie turns to the bartender and asks for a gun. The bartender hardly hesitates and hands it over. There is just simply no scenario where a bartender would hand a loaded gun to a patron they had just met.
Stupidity: A load of cars is in the tunnel with the overhead lights off, and none of them has thought to put their own lights on (as covered already). Then John gets out of the car, only for one car to suddenly flick its lights on and nearly run him over, having been driving at full speed in the total darkness, apparently.
Stupidity: When the marines get the reactor working, Dr Betruger stabs Veronica and kills her so that she will not be able to reveal his secrets to them. However, he stabs her in the lower back, so it would still give her ample time to tell the marines what he is trying to hide whilst she bleeds out. Surely it would have been easier to stab her in the neck or slit her throat.
Stupidity: At the start of the tanker chase Sanchez shoots at Bond. He manages to get in the cab and throw the driver out, who lands on Sanchez's car. Sanchez then gets in front of Bond and has the ideal opportunity to just shoot the cab up with his machine gun knowing Bond is driving, but he doesn't.
Stupidity: The building is supposed to be without power - at all since the generator has been destroyed - and life support machines are not powered up, but the 3D printers in every room are powered up - so that the good guy can squish the bad guy's head in it, and the elevators, so that the good guys can escape. What sort of hospital has its electric grid rigged in a way that the elevators keep working but critical surgical equipment goes dead the moment the power fails? (01:12:00)
Stupidity: Do the military routinely show up at a civilian's house and then pump thousands of rounds into the house without even verifying if anyone is inside? I've heard of suspension of disbelief, but this scene requires driving it to a vacant lot and abandoning it. (01:11:30)
Stupidity: David was seriously injured by Olivia a few times (e.g, hit by her car and on the head with a baseball bat). When Olivia went into the bedroom, David was able to knock over his chair, get a knife off the floor, and free himself from being duct-taped to the chair. David took the car keys but left the knife on the floor, even though he was weak and vulnerable and Olivia had previously chased and caught him. When David returned to the cabin, Olivia came in with the knife and keys. (01:02:55 - 01:09:49)
Stupidity: Instead of breaking into Gordo's house, covering all the furniture in one room with sheets/thin blankets, and waiting for Gordo to return home in order to kill him via a "dramatic re-enactment" (in an adjacent room which was not shown to the audience), Bill could have taken Gordo anywhere to avoid getting caught or calling the police on himself. Had Bill taken Gordo to his already-"wrapped" motel room, he had enough injuries after the fight to claim self-defense against an intruder. (01:43:20)
Stupidity: After stealing the candy tin full of money, Joey gave it to Matt. Standing in front of the house, Matt opened the tin to see all the cash ($12,600). Joey asked him if anyone saw him, and Matt replied, "No. Let's go before they do." Instead of "hiding" the candy tin in his backpack, Matt carried the tin out in the open - and soon ran into a man wearing a security guard uniform.
Stupidity: Why does a safe house have a skylight? It is a secure building with hardened doors but a window in the roof?
Stupidity: In the film climax, Cassie tells Justin to put his gun on the floor and walk over to her. This he does but it gives Richard the chance to grab the gun, so we can have the usual daft Hollywood ending. Why didn't she simply tell him to kick the gun over to her first to void this?
Stupidity: It's very idiotic that Michael and Karen kept the same security password, even after being harassed and not feeling comfortable with Pete being around them any longer. There's no way the pyramid password should have been kept the same, with Pete being able to enter their home, plant drugs, and frame Michael. Changing your security password, the same password that the lunatic cop once knew, would be the first thing to do after his psycho behavior starts.
Stupidity: When Liz sees the dead deer blocking her lane, instead of merely going around it (using the opposing lane on a rural road without jeopardizing her safety), she exits her vehicle - leaving her three-year-old daughter unattended in the back seat - to "look" at the deer. This furthers the plot by giving the "werewolf" opportunity to attack and kill her... as well as her daughter Miley. (00:42:35)