Stupidity: The "body armor" General Ford and others wear is very bulky and appears to be quite heavy with all the attachments (e.g, flashlights on shoulders). With the protective suit protruding perhaps 8", it would most likely restrict/slow movement, contrary to what soldiers need. Moreover, the body may be protected, but there's no protection for the face/head, leaving them exposed/vulnerable. Today's products tend to be lighter, thinner, and stronger, so would be expected in the future.
Stupidity: Lyla does not like the idea of Mickey fighting and initially does not want him to agree to the fight. Lyla eventually tells him "okay", but he must stop when she tells him to stop. This may give her a reason to go to Dubai, UAE with him, but she is about 8 months pregnant. An international flight has some risks plus she would be far away from her OB-GYN doctor if there were a complication. She should have had enough sense to avoid international flights/traveling so close to her due date.
Stupidity: After Casi changed the tracker on the Navigator, he was sneaking between vehicles to get out of the tow pound. The Whale came and stood in front of the two vehicles Casi was between. Casi stood up and, instead of turning around and running away, rushed TOWARD The Whale in an attempt to get past him. The Whale, much bigger, threw Casi against a vehicle and then onto the garage floor. (01:03:34).
Stupidity: Two things: 1. I find it inconceivable that there is only one Carbon Dioxide Removal Assembly (CDMA) and no spares for a two-year mission. 2. The crew has 20 days to fix an oxygen problem. The commander decides on a 10-day window. 5 days into that window they try to load oxygen from the Kingfisher spacecraft. One is lost into space. Zoe decides to go and fill the other one in the midst of a solar storm that will only last hours. Why take that chance? A few hours wait is still quite possible.
Stupidity: Colette was holding the metal ladle close to the bottom of its long handle and near the top of the hot pot of stew she was serving, and yelled, "Ah." due to her hand getting too hot. She had a towel wrapped around the handle of the pot, but it was that hand that got too hot/burned (not the hand that was holding the metal ladle close to the top of the steaming hot pot of stew). (00:04:48)
Stupidity: Simon has told his wife Christine to never go into his shed/lab where he has dinosaurs chained. Christine is looking for her son Mark. Instead of searching the house (and finding Mark in his bedroom) or asking Simon to check the shed, Christine goes into the shed and is killed by a raptor. (00:02:30 - 00:04:58)
Stupidity: To quietly kill the hotel valet he is replacing, Diabolik throws a knife at him from distance, hits him in the back, and then drags his body in the middle of the street to the nearest manhole, leaving a long streak of blood he does not conceal. If this sounds pretty risky and unsafe especially for a meticulously planned murder, you have also to consider that in the comic book from 1963 this movie otherwise faithfully adapts, Diabolik did nothing this foolish; he quietly killed the guy strangling him next to the spot he'd dump his body into.
Stupidity: It was announced on the radio "to stay inside your homes and to only leave in a state of absolute emergency." Then the house shook from an earthquake. May's mom (Gran) called and said, "I'm not sure you should come right now... the roads aren't safe" and "it's not safe to be driving around out there, especially with the kids." May, who told her mom she had the trip planned, finished packing and said, "Kids, we're leaving." Before driving very far, a "monster" was near her car. (00:01:33 - 00:03:47)