Stupidity: When a cop goes to Kevin's house after being requested by police, he simply knocks on the door and after a few seconds walks away assuming no ones home. Had he actually bothered to announce himself as a cop, Kevin would have opened the door and he would have been found safe.
Stupidity: The Engineer and Fireman of the Polar Express train crew should have known better than to not bend back the the metallic prongs of the cotter pin, which would have prevented the cotter pin from coming loose and causing all those problems in the driving of the train.
Suggested correction: As you yourself stated, the whole thing is likely a dream, where "normal" reality doesn't apply. In the "real world", the train would never be able to do any of the things that it does in the film.
Dream or not, it is still a stupidity of the train crew to not secure a pin that could work itself free of the controls of the locomotive.
Dreams are often unrealistic. There is no mistake.
The entry doesn't say anything about the entire trip to the North Pole being a dream.
Stupidity: Hans keeps a major part of his plan secret from his own team: that the electromagnetic lock will be disabled if the FBI shuts down power to the building. The mercenaries hired as muscle don't need to know the minutiae of the plan, but it seems ludicrous that Theo wasn't told. Theo states on more than one occasion that he can't proceed past a certain point and that he hopes Hans has a plan for the final lock. Evidently, Hans was keeping this information secret simply to amuse himself, which makes little sense considering how much planning went into the heist.
Suggested correction: Or because he simply doesn't trust anyone with that kind of knowledge. He neither trusts them or cares about them, it's all him.
So he trusts that Theo would be on board with all the murder and mayhem, open all the other locks, be in a tactical lookout position when the police try to breach, and drive the getaway vehicle. But he doesn't trust Theo enough to tell him the last lock will open when the power goes out?
It's not about trust; Hans needs Theo to do what he is there for and that is all you mention up to the final lock. He has a plan for the final lock and so there's no need to discuss it with the team, since it won't be any of them responsible.
The more people that know the plan the more chances of someone talking. Especially when they are hired mercenaries.
Theo was already on board with taking hostages and committing murder. Him knowing that the power needed to be shut off to open the last lock doesn't appear to be particularly important information you would need to keep from someone to keep them from talking.
If he's the only one that knows the final step to get the money, then at least up until that moment he is absolutely indispensable to the plan and ensures no-one would double-cross him. In any case I'm not sure being more cautious than necessary really qualifies as "stupidity."
Stupidity: Batman finds the Ice Princess on the edge of the roof, standing on the wall. If she's no longer bound, why didn't she just jump down onto the roof and negate the risk of falling to her death, which she did?
Stupidity: During the film's climax where Santa and his reindeer successfully ascend over Manhattan, the sleigh's rocket engine falls off and apparently is no longer needed. Isn't it rather risky (and foolish) to assume (or hope) that the other cities on his flight path have enough "belief power" to sustain him aloft for the rest of his journey?
Stupidity: Considering Rocky keeps hitting Drago after the bell sounds to end the round in their main event fight shouldn't he be disqualified?
Suggested correction: This is up to the discretion of the ref. If he deems the strikes to not be particularly egregious he can let the fight continue. Even if they are deemed illegal strikes, that doesn't mean that Rocky will be automatically disqualified. The ref can dock a point from Rocky instead, which he very well might have done at some point which we never see. Since Rocky wins by knockout having a point docked doesn't matter.
Stupidity: After hearing the question on the radio station to win the Turbo Man doll and a failed attempt at the pay phone to answer it, Howard and Myron end up running two blocks to the station to answer the question. This is really stupid because the prize was going to the first caller with the answer and in the few min it would take to run to the station two blocks away and finally reach the DJ, many calls would have come in and most likely someone would have won already, way before the men arrived there.
Suggested correction: This isn't a stupidity or a mistake. What else did you expect them to do? Plus, the DJ even later asks if they expected him to actually have a Turbo Doll in the studio, and they both said "yes."
Not only that but, Myron had ripped the phone receiver out so Howard couldn't give the answer to the DJ. Howard and Myron running to the radio station was the only other option they had. At that point, it would only be a matter of if they got to the station in time before somebody could call in with the right answer.
It was a very easy question naming santa's reindeer. Although some people may not quite know them all... most people do. Now if it was a relatively hard question, our two guys probably had a better chance. But all good points made here in all these comments.
Stupidity: If the family is planning a big shopping trip, why would Clark still be in his morning clothes and busy putting presents in the attic as if he didn't know? And why wouldn't have anyone told him or reminded him before leaving the house? It just seems like a plot device using the foolishness of the characters to have him trapped in the attic.
Suggested correction: Some people just aren't good at their job or are too lazy. The cop didn't like the idea of being sent on a possible fake call and didn't put in the extra effort. Or he was simply waiting for someone to ask who it was before identifying himself. Plus the cop would have had no idea Kevin was hiding and not answering the door because he was scared nor that saying he was the police would get him to answer the door, he could have simply thought a kid left alone would answer the door to anyone.
Bishop73
Even if he thought it was a fake call, he still should have identified himself. By doing this, he could have confirmed that Kevin was indeed left alone.
And the script could have been written a 100 different ways to prevent Kevin from being left home alone, but that doesn't mean there's a plot hole or movie mistake.
Bishop73
Creating series of silly explanations for obvious mistakes/plotholes never resolves them. He should have identified himself regardless of the circumstances.
Exactly.
Perhaps the officer's failure to identify himself (as well as other deficiencies in the way he responded to the call) would more accurately be classified as a "character mistake"? This may result in fewer criticisms (corrections) while not negating the "stupidity."
KeyZOid
Maybe it should be. Because he acted much too unprofessionally for a police officer.