Stupidity: When they first arrive on Planet Zero, Victor runs his hand through the mysterious green liquid on the planet surface. No scientist in their right mind would ever willingly attempt to touch a body part to an unknown substance. He had no way of knowing if the substance was toxic, corrosive, incendiary, hypothermic, etc. Moreover, none of his companions try to warn him against doing so.
Stupidity: The bad guys should have just shot Paul and his backup during the standoff rather than risking another impediment.
Stupidity: When Susan is on the balcony with the man trying to kill her, she pulls out her gun with one hand (she's leaning on the other hand). He says she won't shoot because the gun's magazine has fallen out and Susan gives up and drops the gun. However, if there is a round in the chamber, the gun can still fire without a magazine in it. As trained as Susan is suppose to be, she should know this. But, if there's not a round in the chamber, then, as a trained agent, Susan is ineptly prepared to use her gun. If there's not a round in the chamber, pulling the trigger will not fire the gun nor will pulling the trigger chamber a round. But she would need both hands to chamber a round and she only has one hand free. There is the occasional gun that has a magazine disconnect safety, but it would be stupid for field agents to have one since they may be in a situation where they need to fire without a magazine in (such as this situation).
Stupidity: When the Pteradons are loose and flying over the crowds, people run from inside buildings out into the open where the birds are attacking people. (01:22:00)
Suggested correction: A person is smart, people are stupid. A crowd in a panic would do exactly that sort of thing. Like trampling over each other running in panic from a shooting or a fire when not needed. It's the nature of panic in humans as a group to act stupid. It's not a movie mistake. It's actually one of the more realistic parts of the film.
Suggested correction: The dinosaurs were also breaking into/attacking people inside, so they weren't safe no matter what.
True, but one option is certainly safer than the other.
Stupidity: Very soon after Damon is stranded, one of the many satellites around Mars inevitably picks up the fact that he has moved various objects around his site, indicating that he's still alive. Yet it never occurs to him that this would obviously, eventually happen. In which case, his best option would be to simply spell out a message with debris and stay put instead of planning some 50-day journey.
Stupidity: At the end of the plane chase Bond fails to finish off Hinx. Regardless whether he thinks he's dead or not, with a licence to kill he should have made sure.
Stupidity: Immediately after Unkar Plutt makes Rey a generous offer for BB-8 and she refuses, he tells someone over his communicator to follow her and bring back the droid. He should have at least waited until she was out of earshot before he said that, especially if he was trying to be covert about it.
Suggested correction: But he was out of earshot of her.
I posted this immediately after watching the scene in question, and it looked as though Plutt spoke into his communicator right after Rey turned around and went on her way; certainly too soon for her to have gotten more than a few steps away. Also, he spoke at a normal, conversational volume rather than anything that sounded like a whisper or "sotto voce", so unless he was relying on the ambient noise of other nearby activity, I still believe this "stupidity" is valid.
That depends on how sneaky you think Plutt is. Rey walks away in quick paces, so she is out of earshot. Also I don't think it bothers him that much if she heard, she is just a scavenger, what can she do about it?
Rey was definitely out of earshot. Rey walks completely out of the shot, which appears to be about 10 feet away. Unkar Plutt then angrily swipes the portions off the counter and picks up his communicator. At the pace Rey was walking she would have been a considerable distance away from him when he spoke. In addition, Unkar Plutt lowered his voice when he spoke because he was being sneaky. She might have been able to hear him speak, but it is totally reasonable that she wouldn't be close enough to make out exactly what he was saying.