Stupidity: When the army base gets overrun the girl jumps on a soldier and starts biting his neck. The woman soldier that's with him aims her gun at them but doesn't shoot, knowing full well there's no hope for the man. There is utter carnage going on all around them and instead she tries to help him and gets attacked in the same way. This could be a plot hole as well as the girl in question is the one that holds the key to survival.
Stupidity: The bodyguard takes Michael's pistol from him and later shoots the pistol near Michael's ear, deafening him, then beats him a bit and leaves him on the ground. As the bodyguard is walking away he gives Michael his sidearm back by ejecting the magazine and tossing the gun on Michael's body. He however didn't eject the bullet in the chamber. Michael's gun, a Sig Sauer, doesn't have a magazine disconnect which prevents a gun from firing with a magazine removed. This was a safety feature for police. (01:33:00 - 01:37:00)
Stupidity: Since the main people could not delete, or even change their own Facebook accounts; why not contact Facebook support in order for the company to do it for them?
Stupidity: When Sook-Hee walks into Hideko's bedroom before the two of them have sex, she slides the door open when going into the room and never closes it behind her. Once the two of them are in bed together and when they have sex, the door is left the way it is and never closed. Considering a sexual relationship between the two would have been completely forbidden, and, if they were caught, would likely ruin the plot to steal the inheritance money, it seems very foolish of them to ignore the open door, especially taking into account there are other people inside the mansion who could walk by at any moment. (00:41:30)
Stupidity: During the movie, the bad guys keep the main character alive and free to roam the facility at will (even if they made him sign an incriminating form at the very beginning stating he's an inmate) doing absolutely nothing to restrict his freedom till the very end - he even retains personal effects like his broken Rolex and lighter, his wallet full of cash! He breaks into every forbidden area, picks up fights, damages property, escapes multiple times and 'corrupts' the person the whole facility is built for. He is worth absolutely nothing to them and has nobody waiting for him or that will look for him.
Stupidity: Why would they drive all the way to Marylebone Railway Station in central London when Southbury Road station is only a thirty-second drive away?
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: Bridget car keys are lying on the shelves (again) after she has left her bags at the ATM. I suppose they could have taken her car after all when she and Mark try to think of a way to get to the hospital.
Stupidity: Jake uses several Loops and travels all over the world in order to get back on the boat at the end of the film. This was completely unnecessary as only the final Loop in 1942, which was available to him in 2016, was the one he needed to enter despite the fact that its nature should have prevented him from reaching 1943 anyway.
Stupidity: When Doss buried the wounded soldier, leaving one eye out made no sense. It did nothing to help him. All it did was make it easier for the Japanese to spot him. It would've made sense to leave his nose and/or mouth out, so he could breathe. He did not need to see.
Stupidity: At the end of "You're Welcome", Maui puts Moana in a cave and placed a large rock blocking the only known exit. This means, as far as Maui knows, he's trapped a human in a cave with no food, water or exit as he didn't know Moana could make a very lucky escape. Basically Maui was going to leave Moana to starve to death so he could take her boat.
Stupidity: The protagonists need to know what Pope is planning with his drug shipments, in secret. So they sneak under a false name into Pope's party and... the policewoman goes dancing with Pope, who knows her and that she is a police officer! Good that nobody asks her anything - she'd have no way to explain her presence! At no point it is even hinted that he was just about to go upstairs, why would he, after all, with all those guests? And their secret mission continues with the alarm being triggered and Ice Cube KTFOing guards. Some stealthy mission, and they are even captured at the end! And even after all these epic fails, they just assume that Pope is not going to change anything about the shipment details. And to make all of this even worse, they know about the port commissioner situation, they talk about it and how necessary it is for Pope to control the commissioner, but don't take half a second to mention his name, which is all it takes for AJ later in the movie to 'remember' that he's been bribed.
Stupidity: Gus is a blatant example of Deus Ex Machina. 1: The % of his pod malfuntion was too low. They mention multiple times how low the chances of a pod malfunction are (Jim's is the first in history), and then it happens twice? Jim's med-scanned him but Gus' didn't (?) so he had 610 things wrong with him. So he woke up dying 2: Gus' existence has only one objective: to give Jim the armband. 3: Before anything else can happen with Gus, he dies conveniently. Gus' existence had no other reason. We didn't care about him emotionally. He didn't advance the plot. He provided no new info or answers to questions. (failure cascade is easily discernible by Jim once he has access to the bridge) It would have been easier to just let Jim find an armband/access another way. DXM: holder of the macguffin magically appears (pod failure) delivers the macguffin (armband + code) goes away (dies without explanation) it's downright shameful.
Stupidity: In a flashback scene, a mother, father and daughter are taking pictures of Norm and two other polar bears. The daughter decides to run up to the three polar bears, but the parents appear to do nothing about it. The polar bears could have been a threat to their daughter for all they knew. (00:04:25)