Stupidity: Ultimately, it did wind up working. However when they shoved the antidote vial into Claire's purse and got George's attention so he would eat her, this was an insanely stupid move. 1. They had no way of knowing if he would actually choose to eat her if he even grabbed her in the first place. Before then he'd been crushing people and even threw the helicopter pilot miles off the building while they watched that happen. 2. The antidote was in a plastic polymer like tube designed to hold the substance inside it while submerged in liquid nitrogen containment. Even if the gorilla's stomach acid could eat through the vial to get to the antidote, it would take hours for it to get through a material like that. 3. Gorillas are herbivores, so it wouldn't have tried to eat a person in the first place. (01:17:55)
Stupidity: Nobody in their right minds would take a nine-year-old child on a dangerous mission to locate and destroy a marauding, giant shark, a project that has already cost a number of lives.
Stupidity: After the team break Solomon Lane out of custody, they drive around Paris with him in the front seat of their car. Lane is still wearing a straightjacket, bound in chains and has a black bag over his head. The IMF team drive him through crowded streets, past multiple police cars in full view of everyone just minutes after an armoured convoy transporting a dangerous prisoner (who everyone is now looking for) has been attacked. None of the Parisian police seem to notice this and none of the IMF team questions the tactical soundness of this approach.
Suggested correction: What's stupid about this approach? The IMF team is trusting that with their skills and experience they can easily evade any police that spot them. Which of course they do. Placing Lane in the trunk would have kept him out of sight but that doesn't really matter because they weren't planning on sneaking him out, they were planning on a quick escape.
Stupidity: When Greg volunteers to watch the security monitors to see if the creatures can affect people through a screen, no-one even thinks to remain in the room with him to cover up the monitors with a blanket, towel or something similar in case the creatures' power can be transmitted that way. They tied him to a chair to reduce his chances of committing suicide, so they certainly thought there was a possibility that he would be in danger.
Stupidity: Why does the team choose to enter the shimmer from Area X and then trek for miles to the lighthouse? They could travel by sea and stage an amphibious landing on the shore right at the foot of the lighthouse. Obviously this would make for a very short movie, but this choice still needs to be explained in the plot.
Suggested correction: I thought it was an obvious tactical choice to go by land. If the mysterious shimmer radiates in all directions for miles, as it seems to in the movie, then it would also radiate for miles out to sea. A recon team is going to have a lot more options to deal with any "weirdness" on the ground rather than on a boat or in the water. (Also, the book "Annihilation" on which the movie is based makes it clear that there are some really big, nasty things swimming around in the water!).
Stupidity: When Han tells Drydon Vos that he and Tobias will steal unrefined coaxium from the mines on Kessel, Vos initially says no, as Crimson Dawn's relationship with the Empire would be at risk. Han then explains that the Empire wouldn't know they were working for Crimson Dawn. Vos then agrees but insists his top lieutenant Qi'ra accompany them, even though she is a known associate of Crimson Dawn and literally has their symbol branded on her wrist.
Stupidity: During the auction, we see the dinosaurs are brought into the room and placed in the middle. Thus blocking half of the bidders from the auctioneer's view. (01:16:40)
Stupidity: Why weren't any of the guards thinking of running to the base of the crane to stop it? Surely there was a more than fair chance to capture Frypan as he had to stay up there and swing the bus to outside of the wall and lower it. Not only does that take a long time, he had to climb back down again.
Stupidity: Zoe and her team go into the medical university to get medical supplies for their camp and Lily. As they are leaving, Zoe sees the Epidemiology room where she used to work and waits, letting her team run off leaving her behind and then goes into the room alone so she can get pictures and some small bottles. Letting her team run off leaving her by herself in a zombie infested building in a city without telling her team that she's not following them. And this did lead to her having to shoot at a zombie that jumped her, alerting the other zombies around, and is what got Frank killed and lead to the smart zombie stowing away on their Hummers and sneaking into their camp. (00:29:35)
Stupidity: The coast cities should have an alarm that detects the Kaijuns. If they do, they should work when the beasts are few miles away from the shore in order to give the people time to get to the shelters. Instead of that there are still people on the streets in Japan and on the docks in Los Angeles (in the flashback) while the kaijuns arrive from the sea.
Stupidity: The team raids the house and locates 5 people inside deemed to be Russian operatives. They are subdued and placed on their knees, while some of the team works on gathering intel from the home. The subjects should have been handcuffed/zip-tied. Since they were not they were able to grab stashed weapons and cause a gun fight which led to one of the entry team's members being killed and all the Russian operatives killed. It's common knowledge to restrain people. Cops and military always restrain. (00:04:00 - 00:12:00)
Stupidity: A-X-L was supposed to be a highly sophisticated and intelligent robotic dog yet it let Sam torch it (without even trying to back away from the flames) and let drones attack it on two separate occasions, each resulting in A-X-L being incapacitated. A-X-L also fell and rolled down a hill, smashing itself. An advanced machine should be able to stay upright! It also seems odd and out-dated that a robot would run on gasoline.
Stupidity: Outside the bank, Mike and the first merc are having a shoot out across the parking lot. There is lots of room between them and around them. Yet a random construction worker, with a clear view of this shoot out happening, suddenly decides to take off running into the line of fire between the cops and the robbers and gets shot in the leg. Their was no reason for him to suddenly decide to run between them shooting at each other into the line of fire. (00:44:35)
Stupidity: Stephanie empties Emily's large closet, but when she comes back with the movers, lo and behold, all of the dead person's belongings are back. They are back though exactly as they were with superhuman inch-perfect precision. Since this movie does not have a supernatural element, that appears really silly. (01:00:30)
Stupidity: During the ghost chase montage, why would Velma look for her glasses with her hand in midair instead than on the ground? No matter how nearsighted you are, the closest wall, or obstacle, is meters away and you'll never find your glasses anywhere but the floor. She does it for a longer time than anyone would. (00:52:40)
Stupidity: At the very beginning of the movie, law enforcement is depicted executing a no-knock warrant. They approach a house surreptitiously and use a ram to open the door with no warning. When they arrived at the scene, all the cars and trucks in the raid were using flashing lights and wailing sirens. So much for the element of surprise.
Stupidity: After Roy escaped from the factory, he encountered a metal garage-door-type gate that was open at the bottom to the height of his knees. Trying to sneak away and in obvious pain from his injuries, it would have been quicker, quieter, and probably less painful if he crawled through the opening. Instead, Roy pulled downward on the chains, making a lot of noise, and it didn't even get the gate halfway up before he bent over to get out. The gate went up more after he stopped pulling on the chain. (01:15:29)
Stupidity: When they raid the warehouse as the criminals are trying to leave town, they load the girls into.a white van. A man (Bruce Willis) wearing a ski mask gets out of the passenger side and covers with his pistol as they load the girls into the van. The entire time the slide on his weapon is back, so the gun is not ready to fire.
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: When the police officer goes to Mac's foreclosed house and asks Lucas (who just came out) for identification, Lucas does not start looking for his wallet/ID. Instead, Lucas tells the officer he thought the auction was that day and was interested in buying the property because he needs space for his horses to run. Before Lucas produces ID, the officer gets another call and has to leave. The officer leaves without even jotting down the license plate number of the SUV. (00:39:58)