Stupidity: An explanation is given for the reason why the bombs planted on the Gundam are not activated by remote control (they have plastic explosive in the regiment but not remote controls!), but no reason why they set the timer for the explosion to 30 minutes, way too much to be of any use in combat against the Gundam. Moreover, if the vulnerable spot of the Gundam shield were situated where it explodes at the beginning, it'd be completely useless.
Stupidity: Yoshi, Mario's sidekick who constantly follows him on dangerous adventures and has gone on dangerous adventures by himself, gets scared shitless when confronted by Riptor. This is not how Yoshi would act in a situation like this.
Stupidity: After Bernie discovers a treatment for the infection, radiotherapy, everything goes back to normal. Except the contagion is airborne (which is why they were going to flush the entire ship's atmosphere), so they're just going to re-infect themselves in a few hours. And there's only one room on the ship that can be exposed to stellar radiation, so there's no way to clean the atmosphere either.
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: On 8/12/04, Hope specifically told everyone that when the coin was thrown into the force field, there would be a bright flash and that they shouldn't look at the forcefield when this was done. But all three times that the coin was thrown at the force field that day and the next, everyone looked right at it the whole time, and then recoiled in pain at the flash that inevitably occurred.
When in Rome - S1-E3
Stupidity: A supposedly covert camera is placed in plain sight on a wall in a crowded room, with a prominent antenna showing, and a blinking blue light. (00:16:55)
Stupidity: The inspector knows that his house has been bugged; he does not know how many bugs and cameras are there, he just knows there are some. He does find a bunch of them with great ease when he gets back home - making you wonder how could he have ignored them to begin with, since all it takes is for him to raise his eyes, they are fairly big black cameras who do not camouflage at all for the most part. He then proceeds to make a phone call to the big baddie from his landline. Nobody in their right mind would do such a thing. Heck, you wouldn't want to use your home phone for such a call even if you didn't know that someone just put bugs all over your house.
The Tale of the Dream Girl - S3-E10
Stupidity: A boy walking through the bowling alley stops and lets Johnny pass, even though Johnny is supposed to be a ghost no one can see.
Stupidity: Eve, the assassin trying to kill the Senator, tells Cole to move or she'll shoot through him, rather than just shooting him. She already killed an agent by shooting him in the back and had plenty of time to just shoot Cole, so there's no reason for her to avoid killing him.
The Kidnapped Prime Minister - S2-E8
Stupidity: In the episode, Hastings stalks Mrs. Daniels, being parked for hours literally in front of her windows, and the army surrounds the destroyed family mansion 'hiding' behind bushes totally visible, not scattered and standing in a way that makes them perfect targets. Nobody knows the first thing about secrecy.
Stupidity: Ray, Avi and Lena covered up a murder. Ray tells Avi that Lena rented a car in The Dead guy's name, and he needs Avi to drive down south, use his passport at the border, and then to fly to Mexico City. The Dead guy's passport has been altered with a picture of Avi, however still in the name of The Dead guy, Varick. All border crossings and airports have security cameras. If they ever want to look into Varick's disappearance they can search his name and see it is not him at the border or airport. (00:42:23 - 00:43:00)
Storm Before the Calm: Part II - S1-E38
Stupidity: Shane could have easily avoided the blast from Lothor by simply flying away to dodge it. Instead, he just hovers over him and allows his Battlizer to be destroyed.
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.
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.