Stupidity: Catherine, wearing a dress and coat, was outside in the snow chopping firewood while her teenaged son sat nearby playing video games on his tablet. This could also fall under "plot hole" because having the son close by made him available to try to help his mom when Pryce attacked her (with the intent to rape). (00:36:40 - 00:37:15)
Stupidity: The ending has a bit of a twist; apparently, octogenarian college professor Morgan Freeman somehow chased down and murdered offscreen 6'3" professional assassin Vernon Davis. That's not the toughest part to swallow, though; he also sent the two detectives (one of whom he is not even supposed to know of) via UPS 2-day delivery mail some body parts of his victim. We don't know which part Lavazzi gets (genitalia were mentioned earlier), but Boyd gets the eyes and decides to eat them. For starters, unrefrigerated 2-3 day old eyes would never look as pristine as the ones Boyd gets. Also, Morgan Freeman mentioned earlier in the movie that for the power of Muti to be effective, the body parts need to be taken from a victim that is alive, screaming, and eaten only mixed with herbs and other catalysts. So what the detective does doesn't make sense even in the movie lore.
Stupidity: There were three vehicles parked in front of Rosie's Cafe when the Virtuoso arrived before 5:00 PM. As he walked past the vehicles, he surreptitiously took photos of the license plates to help him identify the likely target. The Waitress' Jeep was parked apart from these vehicles, on the side of the restaurant. The Virtuoso went by the restaurant's front windows where the target possibly could see him and took a photo of the Jeep's plate. (The fact that no-one noticed is irrelevant).
Stupidity: There is a scene in which the phone rings back at the house and Andy goes to answer it. None of the henchman respond immediately, but instead WAIT for him to almost answer the phone before becoming making a move. You would think they would yell at him to not answer it or have one of them rush to guard the phone the moment it rings. Obviously the entire scene was done this way for the sole purpose of suspense.
Stupidity: The highly trained commandos who knew everything about the NSA base and penetrated it during a perfectly planned operation through weapons and devices that pierce steel like butter, decided to stand outside the barn (so they knew something valuable was there) and its wooden door. It even has a direct line to the command center.
Stupidity: Rick tries to kill Frank at his boathouse by dumping gasoline all over the place and using Ray Coleman's lighter that Frank had. At this point, Rick has gasoline over his arm, but instead of properly cleaning it, he opens the lighter immediately and has his arm burned. Surely a criminal genius like Rick wouldn't have risked this as this is a loose end. Further mention goes to when he has the bathroom door open for no reason while medicating the burn mark, which enables his wife to see him and discover who he really is.
Stupidity: Johnny bleaches and cuts Ponyboy's hair and cuts and washes his own, thinking that would make them not fit the pictures of them. They look the same just with blonde hair and not greasy hair.
Suggested correction: I think you are right to a certain extent, but not necessarily when things are put in perspective. For example, they were "Greasers" and a certain image was attached to this status. Something like washing their hair would make them less noticeable among "Soc's" and other non-Greaser statuses. Anyone looking for them would not automatically assume they washed their hair or had the time to get hair cuts and bleaching while "on the lam." If an APB went out, it would contain their usual appearances.
Stupidity: Lea had two "Notice of Auction" printouts (the correct one and the one she lied about to detectives) in her small purse when she had Casi meet her at a restaurant. Lea excused herself to go to the bathroom but did not take her purse with her. Women almost always take their purses with them and Lea should have, considering she had papers inside she didn't want Casi to see. While Lea was gone, Casi looked at the printouts and then knew Lea was lying to him about the Navigator's auction date. (00:32:33 - 00:35:04)
Stupidity: Molly was being hunted and didn't know if she could trust Rayburn when he encountered her. Rayburn told Molly that he wanted to help, wouldn't hurt her, put a blanket around her, and even carried her in the woods for some distance. When he put her on the ground (along with his backpack and rifle) to go find the rope to open the pitfall doors and had his back turned, Molly got out from under the blanket and hid nearby. Rayburn quickly found Molly, and Molly made a lame attempt at attacking him with some kind of club. The next day when Rayburn and Molly were in Rayburn's house and her hunter showed up and attacked Rayburn, Molly grabbed Rayburn's rifle and fired several shots at the hunter. Molly obviously knew how to use a rifle, so it was asinine for her to have hidden from Rayburn the previously night without taking his rifle (or the blanket). (00:36:22)
Stupidity: When he's using carbon monoxide to poison the corrupt detective Frank Masters, the windows in the car were operated by the key fob. Unusual, but OK. Maybe. But the detective could've simply opened the doors after McCaul left him in there. The door worked when he was forced into the car. (01:24:30)
Stupidity: Anyone with a job in the White House would have to be known to the Secret Service on a daily basis, so the two Secret Service agents that find Cory the janitor should have been aware of his identity without him having to state who he was and that he worked there.
Stupidity: I seriously doubt that any Mexican Mafia cartel operating here in the U.S. would waste their time eliminating two simple patrol officers. There's nothing to gain by doing so, and it would bring a war between themselves and the police, which in return would bring hundreds of arrests of key members, drug busts, raids of their operations within Southern Cali, etc. They wouldn't risk their business taking millions of loss of revenue all to kill two patrol beat cops.
Stupidity: Paul Manfield (Arthur Pope) and his family have been hiding from and eluding the FBI for fifteen years, but Paul gets so intoxicated one night that he loudly sings "Pretty Woman" walking toward his house - where neighbors could hear - and yells that he is not Paul, he is Arthur Pope. (00:52:18)
Suggested correction: People do seriously stupid things when they are drunk, and Manfield/Pope is very, very drunk.