Always a Godmother, Never a God - S6-E4
Stupidity: Rory arrives in Star's Hollow for the baptism. She parks presumably near the church. When she gets out of the car, she does not have a purse or car keys in hand. She apparently left the car unlocked and left the keys in it. It's just plain dumb.
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.
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: Andor and Luthen set a vehicle to drive and distract the security team. The vehicle is destroyed, and they immediately round the corner in full view of the team on a speeder and drive away, then blow up the vehicle. They could have driven away on any number of other streets without revealing that they weren't in the vehicle, keeping their escape secret. And if they blew it up before the team looked too closely they might have even been deemed to have been killed in the crash.
Stupidity: S50: Starting in episode 120 Genoa City had a celebratory gala at the GCAC. After the gala everyone that was staying long-term at the Grand Phoenix Hotel is now staying at the GCAC. The GCAC long-term rates must be much better to make everyone move out of the Grand Phoenix.
Stupidity: Adam, Jason's replacement on Bravo team is operating as Bravo 1. He's in the midst of reloading his carbine rifle with a fresh magazine when he sees a suicide bomber running towards his team so instead of drawing his pistol which takes 0.7-0.8 seconds; he's a trained professional so that timing is reasonable; he instead charges the suicide bomber and dies in the explosion. It would've taken less time to shoot the threat than to charge him. (00:07:00 - 00:08:00)
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: 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)
From Injustice Came the Way to Describe Justice - S1-E5
Stupidity: The police raid an apartment in search of guns. They should have used a ballistic shield for the point man to make entry and hit the apartment with a concussion device (flash-bang). The police officer who took a stomach full of lead would have more than likely survived had they been properly equipped. Ballistic shields have been around since 1977. This story takes place in 1992. (00:49:17)
Stupidity: The gas station attendant can (at least hypothetically, he turns out to be wrong) recognise someone who did a hit-and-run a long distance away at night, but somehow he does not recognise in court the client of the station who was with him at the same time and interacted with him for a few minutes.
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.
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: When Brass and Sarah enter the locked storage cellar where the boys are hidden, Greg, a graduated rookie, straggles along behind them when he should have known better to stay put. As anyone could have come along and locked that cellar door behind them, trapping them inside.
The Night of the Firebrand - S3-E2
Stupidity: West is introduced to, then knocked unconscious by Vixen as she hides a club behind her back. A trained Secret Service agent like West would not have let his guard down in this situation, as the entire fort was awash in bad guys.
Stupidity: Radar takes his glasses off, takes a sip of coffee, then props his clipboard onto the typewriter and accidentally starts typing on the desk calculator. Even if he didn't know his desk well enough to wonder what he laid his clipboard upon AND was so blind he couldn't even orient himself by the desk lamp (which he isn't), he would have felt the difference the instant he touched the keys. Note that he puts his hands on the keys, squints at the clipboard (sic!), then starts typing, he doesn't hammer away right off, which would have added at least a little plausibility to the joke.
Stupidity: The brothers are angry at Leo because they say he's responsible for them dying because he chose to save other soldiers instead of them, Leo also blames himself for the same reason and says he should have stayed and gotten them out. But in the flashback it shows Leo helping them and then running off to help other soldiers, after he runs off the brothers are killed just a few seconds later. Even if Leo had chosen to stay with the brother he couldn't have gotten them out in time, the only difference would have been Leo would have died with them, but Leo dies in the same war so he didn't live much longer. Leo's guilt and the brothers' blame don't make any sense at all.
Stupidity: After the accident, Dawn is in spirit form on the road trying to wave down an oncoming car (driven by Martha Kent). Dawn doesn't know she's a spirit that can pass through objects at that point. Since Martha can't see her, she keeps driving straight towards Dawn. Dawn sees the vehicle isn't slowing down and instead of simply stepping out of the way to avoid getting hit, she turns her back, revealing to the audience that objects can pass through her now.
Day 4: 12:00 A.M.-1:00 A.M. - S4-E18
Stupidity: After leaving the power plant to pursue the terrorists and retrieve the nuclear football, Jack orders the helicopter to take out the first Jeep. After he realises parts of the football are missing, why does he not order the helicopter to pursue and take out the other Jeep, preventing any further trouble from Marwan? (End of season 4's story, most likely).