Stupidity: Dr. Greg seems to catch some of the more obvious quirks of inmates attempting to take a large vial or bottle from the cabinet. Yet he doesn't seem to notice when Lizzie grabs a bottle of pills and pockets them from the rolling cart in front of him. (00:20:15 - 00:20:45)
The Pin-Up - S7-E17
Stupidity: After Erin leaves with the military captain to Camp Lee, John and Maryellen turn around to see John Curtiss nowhere around on the porch where Maryellen left him. So John goes off to look for him, while Maryellen goes in to check The House. John Curtiss is a one-year-old baby who couldn't open a door.
Stupidity: Hard to swallow that a group of vastly experienced policemen smart enough to figure other tricks out (such as the abnormal position of the gun) would be in any doubt about the victim being left or right handed when she is still wearing their watch on the right wrist - and attention is called by Poirot upon that particular detail right from the start.
Stupidity: When Kunte/Toby saws himself free from his leg irons, he removes only the one, and then runs off into the night, dragging the other one behind him, which makes no sense, and is quite audibly heard in the near distance.
He Lokomaika'i Ka Manu O Kaiona - S8-E20
Stupidity: After being stripped of their weapons while looking for terrorists in the jungle, Steve and Catherine meet up with Jerry, who has not had his gear taken, but didn't bring a gun because he's only a consultant. Some time later, after they open some coconuts using a small machete Jerry had on him, they hear gunshots, and go over to investigate, finding two dead hunters. They take a pistol of one of the hunters right before encountering the terrorists. So far, so good. But then to fight the terrorists, Steve has Catherine provide cover fire with the handgun while he attacks them unarmed, and hands Jerry a rock when he asks what he's supposed to do. Why doesn't one of them take the machete? You can still see it on Jerry's back.
Suggested correction: If you are not trained in fighting with a machete, doing so may well do more harm than good to you. Hard to believe that Superguy Steve isn't, though.
Stupidity: Linda suffers a gunshot while in the hospital. The doctor calls for a trauma team that responds immediately to take her to surgery. The next time Linda is shown the trauma team is still taking her to surgery through the hospital hallways, and the whole Reagan family made it to the hospital and in the hallway as Linda is being taken to surgery. The hospital hallways must be long or the trauma team took the long way to surgery to allow the family to be there. (00:03:28 - 00:05:57)
Stupidity: Why do they always have to go through that washing machine setup in the laundromat when they have a great functioning elevator to the lab?
Suggested correction: Why would Gus go through the process of hiding the lab entrance stairs behind a washing machine but leave access to a freight elevator wide open? The elevator would be just as hidden and probably locked up. Not to mention it would be slower to take than simply walking downstairs.
Stupidity: Harold isn't sure whether to trust the flash drive Claire gives him, worrying connecting it to his laptop will send Samaritan all his personal connections. Somehow it doesn't occur to him to just use a completely disconnected / airgapped laptop, in a Faraday cage or similar like the one he kept Root in. If the flash drive had malicious code on it, nothing could be transmitted anyway.
Camp Redwood - S9-E1
Stupidity: Brooke leaves her apartment window open as she sleeps, even after telling her friends that serial killers (like The Night Stalker) strike during the summer when everybody leaves their windows open.
Stupidity: Mouch is investigating an arson allegation. He states to a lady he's going to do his thing and speak to some of the residents. As he goes down the hall to speak with the residents he passes a huge stain on the carpet that looks like blood or something and walks right past it without stopping. (00:23:57)
Who, What, Where, Wendigo? - S2-E10
Stupidity: Dwight, Audrey, and Nathan all know Dwight's trouble is that all bullets are attracted to him, so why is he with them when they go looking for the killer, knowing every one is using a gun?
Log 81: The Long Walk - S1-E14
Stupidity: They are looking for a red convertible. No other description of the car. A red convertible pulls up behind them and passes them. The ragtop roof is up but it's still matches the description. Doesn't faze them in the least.
Stupidity: The Tomorrow People tend to enjoy walking into and walking out of most scenes rather than teleporting. In particular, when fighting and needing to run away, they'll teleport to get a better fighting vantage instead of teleporting out of the situation.
Backlash of the Hunter - S1-E1
Stupidity: Rockford knows almost nothing about the guy who is tailing him except that he noticed him while he was grabbing a bite with his client. Regardless of that, he sends the same client to seduce him, just assuming that he won't be able to recognize her. And it works. Is Lindsay Wagner this hard to forget, that this guy just an hour or two later isn't able to tell it's the same woman his target was meeting?
Living Hell - S1-E8
Stupidity: When the villain reveals to the doctor that he plans to transplant her brain into his own head, the doctor tells him it isn't possible because the brain can't survive outside the head. Forgetting to mention the fact that he will die the instant he takes his own brain out, making it rather difficult to complete the procedure, that is, if he didn't pass out from the pain of opening up his own skull first.
Stupidity: Despite being a high-profile fugitive who was a local celebrity in his previous life, Saul does very little to alter his physical appearance, settling on just a mustache and glasses. Growing a beard, wearing a hairpiece, and altering his speaking voice around others would have gone a long way in preventing him from being made.
Stupidity: Amazing how people on this show, like The Accused here and in the earlier episode "The Chef", are leaving their doors unlocked or no explanations given as to how the actual killer planted the evidence.
405 Method Not Allowed - S4-E5
Stupidity: Elliot and his crew are trying to take down the Dark Army and Whiterose, they are being monitored by them via surveillance vans which Elliot just burned, etc. However, with Elliot and friends trying to be secretive he somehow manages to text Phillip Price on his cell phone about Tyrell. Phones are the easiest to intercept. Whiterose doesn't trust Phillip and plans on killing Elliot once their projects transferred to Africa. (00:07:20)