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: 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: At the start, when the bank robbers pile into the car, Frank flips a switch and the licence plate changes...out in full view of the public. Given how well-prepared Frank is demonstrated to be, that's absolutely something he would have done in private, before arriving at the bank.
Suggested correction: The plate is changed after the robbery for a reason. By allowing plate A to be seen during the robbery the information will be relayed to the police that a car with registration plate A is involved. Swapping to plate B after the robbery ensures that police will see plate B and know that the car is not involved.
But the point is he drives up to the bank with plate A on display. The robbers pile in and he switches to plate B. So any witnesses have seen both plates (plus the fact that the car switched plates, doubly suspicious). Whereas if he'd switched to plate B while out of view in the car park, he'd still have a "clean" plate to use.
Stupidity: Rick tries to kill Frank at his boathouse by dumping gasoline all over the place and using Ray Coleman's lighter that Frank had. At this point, Rick has gasoline over his arm, but instead of properly cleaning it, he opens the lighter immediately and has his arm burned. Surely a criminal genius like Rick wouldn't have risked this as this is a loose end. Further mention goes to when he has the bathroom door open for no reason while medicating the burn mark, which enables his wife to see him and discover who he really is.
Stupidity: When he's using carbon monoxide to poison the corrupt detective Frank Masters, the windows in the car were operated by the key fob. Unusual, but OK. Maybe. But the detective could've simply opened the doors after McCaul left him in there. The door worked when he was forced into the car. (01:24:30)
Stupidity: When the duke approaches the wall at the end, Snake dives on him and briefly knocks him out. Snake could have easily grabbed his gun back and left the duke unarmed (or even just killed the duke there and then), but just gets up and runs, leaving it with him.
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: If Gabriel and his crew are such incredible hackers, why in the heck would they use a government vehicle that is LoJacked? Even so, wouldn't they be cognizant enough to disable the GPS tracker just in case?
Stupidity: When Steve Martin reaches the beach with the wheelchair, he tips it over, giving the illusion that he fell out of it. However, with where he starts crawling on the beach, it's tipped the wrong way. If it was that way, he would've been on the other side of it. A clever con-artist should know better.
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: After the Defranco "assassination" Rollie learns he is a target and survives two attempts on his life. But instead of leaving town or finding somewhere else to hide for the night, he spends the night in his own apartment (even though he was well aware the killers knew where he lived). As a result, his girlfriend is killed and he barely escapes alive.
Stupidity: Ilona Bergen's murder happening as shown is laughable; she sees the hand with the syringe coming, slowly, at her, and not only she can't defend herself or avoid it (because, damsels in distress in the 60s, you know), but she does not even scream. There's no way the killer could have been sure, or even take a calculated risk, to murder her in such a way. (00:55:25)
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: Molly was being hunted and didn't know if she could trust Rayburn when he encountered her. Rayburn told Molly that he wanted to help, wouldn't hurt her, put a blanket around her, and even carried her in the woods for some distance. When he put her on the ground (along with his backpack and rifle) to go find the rope to open the pitfall doors and had his back turned, Molly got out from under the blanket and hid nearby. Rayburn quickly found Molly, and Molly made a lame attempt at attacking him with some kind of club. The next day when Rayburn and Molly were in Rayburn's house and her hunter showed up and attacked Rayburn, Molly grabbed Rayburn's rifle and fired several shots at the hunter. Molly obviously knew how to use a rifle, so it was asinine for her to have hidden from Rayburn the previously night without taking his rifle (or the blanket). (00:36:22)
Stupidity: Joe's second homicide aims to be ruled as accidental death, but Joe's plan involves a furious struggle with the guy underwater, who claws and bites at his arm, as he applies pressure to his shoulder and neck. Moreover, their struggle happens close to the water surface but the bodyguard who is there does not hear or see anything. (00:35:00)
Stupidity: In the original novel, the attempt on Mrs. Doyle at the temples was made rolling a boulder off a cliff. In this adaptation, the culprit is said to 'dislodge' a large stone from the temple; you can however see that the stone is already dislodged and sticks out from its place on the pillar, and he had no way to know that the Doyles would be in that particular spot, making this attempt to Linnet's life rather nonsensical (requiring also herculean strength, no pun intended). (00:47:40 - 01:39:30)