
Stupidity: When the shuttle arrives with the assassins, O'Niel is shown loading a shotgun, then he carries that gun when he runs to his office. When he leaves his office again to confront the assassins he grabs another shotgun from the locker. Why didn't he just grab the gun he walked in with?

Stupidity: The 1st time Foley enters the warehouse with the woman, 2 guys enter with the wooden box and black bags on top to transfer the bonds, then take it back to the truck. Why enter the warehouse at all when they could've put the bonds in the bag anyway, inside the van? They had no reason to go to the warehouse at all. (00:42:20 - 00:43:25)

Stupidity: Colonel Sharpe retrieves a gun from a locker on the Freedom shuttle. However, said gun is shown lying flat on the floor of the compartment, with no visible means of securing it, which would hardly be standard NASA procedure given the shuttle undergoes a high-G launch, orbital manoeuvres and various other high acceleration events. A loaded gun bouncing around is the last thing anyone would allow on a shuttle. (01:42:39)

Stupidity: Red and his gang have a barn full of stuff and talk about other couples and people they have kidnapped, robbed and probably killed. This indicates they have been in the "game" for a long time and been successful to avoid capture this long yet when Kurt Russell didn't want to get in the car, instead of cutting their losses, they went along with kidnapping his wife and initiating the whole ruse of her never getting in Reds truck which is what led to their downfall. Someone with the experience of this that Red has should know not to take such a big risk with a complicated story.

Stupidity: Mike Roark is supposed to be the director of an agency that is in charge of coordinating all the resources of the city in the event of a natural disaster, but he doesn't know what a "geological event" is, not to mention magma?

Stupidity: Jack has been using Mosley's badge and identification to pass himself off as FBI. He never once uses this trick to commandeer a civilian car for him and John when it would have been the safest way to get to L.A. much sooner.
Suggested correction: Probably because If he did that, the car's owner like Red the bar owner would eventually call the FBI office to get their car back and then the feds would know the make, model, license plate, and the last location of Walsh and the Duke. The police would have caught them in minutes. Walsh had to keep a low profile.

Stupidity: Having become the leader of the universe's most stealthy fighters, he promptly leads them in a Custer-esque noisy frontal charge into a force with known weapon and technology superiority. Zero effort to utilize ANY of their amazing stealth, just have them slaughtered so badly that the planet has to sacrifice animals to save them from extinction.

Stupidity: Dafoe does a lot of looking around while flying the plane. He could have pulled up much sooner. Then he screams and puts his hand to his face, and then he sees the tower and crashes into it. (01:53:29)

Stupidity: Alex, a contract killer, went to the hospital to kill a patient. After parking in the hospital garage, Alex put his car keys under the sun visor, risking the possibility that his car could be stolen. When Alex returned to his vehicle, the keys were not there. A professional or expert assassin should take precautions to assure his getaway car will be there and keep his keys on him. (00:01:45 - 00:04:30)

Stupidity: One of the actors microwaves bullets and then loads one into a weapon. Only problem: she/he (I did not pay attention) puts the round the wrong way around into the magazine. Then the person loads the magazine with the one round visible in the wrong direction into the weapon. I would say that this should not be working. (04:25:00)

Stupidity: Why would 006 put Bond in a self destructing helicopter instead of just shooting him? Being Bond's old partner, he of all people should know how good of an escape artist Bond is.

Stupidity: All that chaos going on at the end of the movie. Gun shots. Screaming. Blowing up police cars. Yet not one neighbor comes out to see what's going on.
Suggested correction: Gunshots and explosions going off at a neighbor's house isn't going to make me go and investigate. It's going to make me call the police and hide in my own house.

Stupidity: Principal Fremont did not even consider the possibility that what Mr. Butler was saying about Lucas could be true. She basically laughed it off ("dismissed" it as absurd). On different occasions, Mr. Butler tried to tell her that he didn't think Lucas was who he pretended or appeared to be and that Lucas was blackmailing him for an 'A' in his English class. Because all of Lucas' grades from his previous school were 'A's, the Principal took for granted that they were legitimately earned despite Mr. Butler's concerns. A school Principal should be willing to at least look into Mr. Butler's accusations against Lucas, not merely blow them off as false. [The fact that Mr. Butler could not be more convincing is also problematic.].

Stupidity: In the freezer you can see the electrical wire power cord that is powering the motor on the wall. She could have easily pulled/ ripped the wire to stop the freezer from working. And when the chemical bomb is in the mixer they could have unplugged the machine which would stop it from going off.

Stupidity: Captain Poison has a fairly good idea of where Solomon buried the diamond. We know this since when he leads the captured Solomon to the spot, there are already several holes dug looking for it. Despite knowing roughly where the diamond is - down to a relatively small area - he makes no serious effort to excavate the ground, instead contenting himself with a handful of incredibly shallow holes.

Stupidity: When the birds gather in the schoolyard, Melanie runs in to warn Annie. Rather than calling the police or fire department for help and then shelter in place until aid arrives (which would take about ten minutes), they instead decide to make a run for it with the children, out in the open, getting attacked by the birds. As it's the 1960s, the schoolhouse presumably has a working phone.

Stupidity: After one of the policemen decides to jump over the railing and right into the angry mob (!), Arthur just easily sneaks by ducking under it and takes a nice stroll that will lead him through an unlocked door. Nobody in the mob he is part of decides to do the same, and you can also see that one of the policemen is turned towards him, but does not even yell at him or move. And of course, with the theater packed with the Gotham elite basically under siege by a mob and guarded by the police, the door is unlocked and unchecked. Why not. (01:02:55)
Suggested correction: The point is they were all too distracted by the tussle to notice Arthur ducking behind the barrier. No cop sees him. The angry mob is controlled by the barrier and not all that large so they haven't taken extra precautions to keep the mob at bay, yet. The door Arthur gets in is probably a fire escape and can't be locked for safety reasons.
I think that with an angry mob worth putting barriers and a big police dispatch, they'd tend to lock the door that is like a 20 feet of walk in a straight line. I mean, they have barriers in front of the stairs, but at the base of the stairs there's an unguarded, unprotected, unlocked door. It's just funny. Not even something in the back or around the corner, no; literally one step to the right of the blockade.

Stupidity: Why did the bad guys even go for Xander as he was snowboarding down the mountainside? First of all, it was impossible for them to even get to him as the mountainside had several cliffs. Secondly, why did so many go? Wouldn't it be clever to have as few as possible leave in case his snowboarding was simply to draw attention away from an ambush? They knew he was an agent by now and should know he could have gotten reinforcements. Thirdly, they could just have simply waited for him to get to them.

Stupidity: The minivan is involved in multiple serious accidents but shows very little damage.