Stupidity: Dr. April (as well as her patient Mrs. B) is nonchalant when her young nephew Zeke brings his dog hit by an automobile into the hospital. Dr. April, continuing to hold her clipboard, tells her nephew she is "not that kind of doctor" and "what you need is a doctor for animals." The doctor-aunt could have at least taken the dog from Zeke's arms to ease his panic and see if there is something obvious she could do to help the dog. Instead, she walks out with Zeke still carrying the dog. (00:02:45)
Stupidity: As soon as Bundy got into the building (instead of when he was still outside), Kaminsky asked him for a "camera check." Bundy had a yellow button with a big star in the center pinned to his jacket's right lapel. Bundy put some fingers next to the button and raised his lapel with the others, making it obvious he was wearing a camera. When Manson got into the lobby (area likely to be under video surveillance), Reese (who saw Bundy and Manson outside) came into the building to give them weapons. (00:03:50)
Stupidity: After the Prince and his entourage unexpectedly arrived at the chalet, Ms. Tilson told Emily that she tried to call but Emily's phone was turned off. Emily replied, "I forgot to charge it last night." A woman (or person) who went to a remote vacant chalet in the mountains during the winter, contracted to watch over the place, would not "forget" to charge her cell phone. Making sure her cell phone was charged (and has reception) would be at or near the top of her list of concerns. (00:09:10)
Stupidity: The protagonist is wearing normal boots atop a spacesuit while being on a moon mission. (01:37:11)
Stupidity: Charlie set her mom's blouse sleeves on fire and mom/Vicky just stood in the same spot, holding her arms (burning sleeves) out in front of her until Andy came and smothered the flames with a blanket. Even children know to "drop and roll" or put fire out by smothering it. (00:22:56)
Stupidity: There is a map of the area on the wall behind Jason as he tells Sam and Ben to "look for anything useful - maps, food, radios, anything." Also, there is a map in the drawer as Sam opens it, but she removes the notice letter "shuttered for budget cuts" and the snowmobile keys. (00:44:43 - 00:45:20)
Stupidity: After eating the bird, why didn't Becky send her phone down inside the bird, but instead climbed down to put her phone inside Hunter's body?
Stupidity: When Poirot's team attacks the Germans, they do it through the cover of gas they release. The Germans are having a good time chatting and not taking the situation seriously when there's a big cloud of noxious gas advancing towards them. Despite Poirot's oh-so-clever plan, they should by all means know that something is coming their way, but they get caught entirely with their pants down.
Stupidity: Grace (?) came out of hiding holding a fire extinguisher upside-down as though prepared to use the fire extinguisher to whack any Allosaurus that approached her. Actually spraying the dinosaur's eyes with the chemical contents of the fire extinguisher - and from a greater distance by using the hose - would have been much more practical and effective as a repellent and thereby less likely to result in getting maimed/killed. (She did not use the fire extinguisher at all). (01:02:20)
Stupidity: After Danny kills Kat on the sidewalk, he just stands there with Rory while the other gang members flee to their vehicles. William comes running out of the Mexican restaurant and Rory tells Danny, "We gotta go, brother. Now." Rory sees William and gets into the vehicle without getting Danny to go with him. The gang drives away with Rory watching out the window as William tackles and fights with Danny. Rory and the rest of the violent gang left behind someone who just passed the initiation. (00:07:10 - 00:07:40)
Stupidity: Don told Allen he'd have to wear a blindfold to his house because he didn't want Allen to know where he lived. Instead of having Allen ride in the cab where he could monitor him to make sure he didn't remove the blindfold, Don made Allen ride in the truck's bed (where Allen did lower the blindfold to use his cell phone). (00:14:24 - 00:17:00)
Stupidity: Instead of Ray freeing himself before the Hangman comes to get him out of the bed of the truck or using his knife to stab the Hangman before he gets hung, Ray lets the Hangman hang him from a tree and knock over the ladder to strangle him. Ray dangles for almost a minute until he fakes his death and drops a fake Rolex, planning on slashing the Hangman's throat when he comes to pick up the watch. Ray, still dangling with the rope around his neck and a hood over his head, is also able to talk. (00:00:47 - 00:02:36)
Stupidity: The cleaning crew can't open doors and stand in front of a large window. They see a couple walking a dog, so they scream, "Hey!" and wave their hands in the air, even though the people are not looking their way. They do not bang on the glass or use their flashlights to try to draw attention. (00:29:13)