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)
Stupidity: Dr. Cocteau's choice to unleash an enhanced Simon Phoenix without any way to restrain him is incredibly reckless and stupid. Even if Simon were to kill Eager Friendly, in the best case situation, you'd still have a madman with total computer access, martial arts knowledge, etc., that you would have no way to rein in. Sure, he can't kill Dr. Cocteau, but what would stop him from say, holding the city hostage or something? Why not add in a kill code or something to keep him in check?
Suggested correction: Who says he didn't? Cocteau has put in mental conditioning compelling Phoenix to kill Edgar Friendly and make him unable to kill Cocteau. Who says he hasn't put in something that makes him kill himself after the deed is done? Or perhaps paralyze him so he can be put back on ice. It's just that Cocteau didn't count on the fact that his henchmen could kill him. He doesn't care about how dangerous he is, not until he has done the deed.
Dr. Cocteau is a narcissistic egomaniac type that would see himself as a king or a god, even. And Simon is making him very angry. He even tells Simon, "you're beginning to be more trouble than you're worth..." Someone with an ego like Cocteau wouldn't stand for Simon's antics for very long. And would happily enjoy putting Simon back in his place by shocking, paralyzing, etc.
But he first needs him to kill Friendly. Until he does that, he'll let him play. He still sees no danger to himself.
Stupidity: With the threat of strangulating Jess, Garriga coerces a false confession from Nicky about the complicity of Jess. Garriga then laughs, calls Nicky out on it, and points out the confession's deficiencies. The film treats the whole scene as an astute reveal à la Sherlock Holmes! Nobody notices, let alone points out, that a coerced confession is worthless. In reality, Garriga would feel very stupid because he almost murdered someone. For the same reason, Jess must feel very angry.
Stupidity: Angela ran over to her neighbor Mr. Charlie when she heard him come home. Angela was complaining that his son and friends make too much noise, do whatever the want, are bringing property values down, act wild/crazy, draw attention to everybody, and she doesn't want the police coming. These may be legitimate complaints, but the way Angela expressed them would bring down property values! Not only was she yelling in the street, she used "m-f-ing" several times, as well as other select words. (00:02:35 - 00:03:07)
Stupidity: The Chief Inspector wants the video cassette back because it shows him committing murder. Yet he spends the entire movie shooting and killing people in public trying to get Johnny and the cassette.
Stupidity: Early in the movie, AMMO and its crew show remarkable prudence in their approach to the drug deal, and a point is made about them following procedure, planning accurately using technology and trying to minimize collateral damage. The sting at the club goes against all of that. At the end of the day, it just consisted of getting close to the target and pulling guns on him in the middle of a crowd of civilians, the exits of the place (the front door even) completely unguarded.
Stupidity: Becky possessed the mysterious key that the four neo-Nazi prison escapees were at the lake house to retrieve. Becky didn't know what the key was for, so did not have a vested interest in it. By first denying that she knew where the key was and later refusing to give it to Dominick, her father was killed. Had Becky simply handed over the key when Dominick asked for it, it is possible no-one would have been hurt/ killed. Becky keeping the key with no importance to her served to further the plot.
Stupidity: Given Louise's character, it makes no sense at all for her to leave Thelma in charge of the money. She's known Thelma for years, and knows fully well how flaky Thelma is. And Louise is shown as a person who lives by "If you want something right, you've gotta do it yourself". She's responsible, perhaps even uptight, at that point in the movie. So it defies everything about her character that she would let Thelma guard the money - it smells like a device set up just to allow the money to be stolen.
Stupidity: Carl buries the case with the money in a field by a fence. He looks at the fence line and wonders how he is going to be able to find the spot when he returns. He plants an orange ice scrapper to mark the spot. The scrapper is only 6-8 inches, but it's the middle of winter in Minnesota. The scrapper will be buried by snow. He should have marked the spot by tying something on the fence. (01:18:26)
Stupidity: It was very idiotic of Turner, who is an experienced serial killer, to not only knock out and take Julie prisoner, but to attack Kale as well, considering the recent circumstances. The police and Julie didn't believe Kale, and Turner suddenly goes on a rampage? He took a huge risk when he attacked Kale and could have very easily blown his cover.
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: Why would the tow driver go around Deacon's truck in the one-way dead-end parking lot to pick it up from the front? He'd have to back it up on the hook, and Deacon's truck would be in Park, making it impossible. There's a reason tow trucks hook up vehicles by the drive axle ends. (00:08:40)
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: 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: At the end of the movie during the shootout. Cops would not engage in automatic gun fire with dozens of civilians in direct cross fire. Why not get a chopper and chase them down a bit maybe in an open area with fewer civilians? Then maybe engage in gunfire.
Stupidity: In the flashback about the way the victim was poisoned, it would seem that the murderer straight out went to a waitress and handed them a single chalice of poisoned champagne, ordering the waitress to give that exact glass to the victim. That's just a little bit absurd; if it's a flashback based on a testimony, the case should have been solved in 0.1 minutes once the waitress says that that very well known person asked them to bring a glass to the victim - it's a request highly unusual and that would be easily remembered. If it's just some wild guess of the detective, that's a mighty strange way to imagine how things went, rather than just the killer slipping venom in the victim's glass when they were not looking. (01:04:00)
Stupidity: In the bar scene, Jack gets into a fight with a guy he busted a few years back, then Reggie turns to the bartender and asks for a gun. The bartender hardly hesitates and hands it over. There is just simply no scenario where a bartender would hand a loaded gun to a patron they had just met.
Stupidity: A movie always needs extra conflict, but Julie's reasoning for walking out on Marcus and Mike is one of the dumbest. "If his wife can find us, I'm a LOT better off on my own." What sort of logic is that? She's the wife of his best friend. Of course she knows where he lives. (01:32:45)
Stupidity: One of the major reveals and plot twists of the movie lies in the fact that a certain character is an accomplice of the medium. The reveal, though, does not explain at all how said individual managed to fool Poirot; the trick briefly shown involves a simple rope pull to open a door. Poirot was looking exactly for that kind of trick, paces around the room constantly on maximum alert, and examines the door itself later. Likewise, it does not explain where and how they could hide the stuffed animal.
