
Stupidity: After eventually arriving at the stadium, why didn't Ash tell anyone that he was late due to getting kidnapped by Team Rocket? He arrived with half of his Pokémon exhausted and subsequently lost his battle. If he informed everyone about his situation, his battle with Ritchie would likely have been postponed until tomorrow, giving him some much-needed time to rest, which would have given him a bigger chance to win.

The Farting Sex Tourist - S1-E4
Stupidity: Joel finds prints in Serbian and is stressed because they'll never find someone to translate Serbian in Santa Clarita, goes to great lengths to interact with the principal's Serbian grandmother, etc. Google translate can understand Serbian just fine, but this doesn't even occur to him.
Suggested correction: Except the 16th century Serbian alphabet isn't available to most people to type into google translate. Plus the script used makes it difficult to distinguish which character is which sometimes even if you could find characters to cut and paste tediously into google translate.

Stupidity: Sir Topham Hatt is cross with both Percy and James. But why is James being blamed? He had no idea that Sir Topham Hatt didn't actually say that he had to stay in the shed and wait for him. James shouldn't have been blamed since he had thought Sir Topham Hatt actually said that and Percy should've been the only one blamed.

Episode #3.2 - S3-E2
Stupidity: Throughout the whole episode, no effort at all is made to find out where were the chocolates purchased, and the bottle of champagne that accompanied the box(es) is completely ignored, not even addressed in a throwaway line (such as that it's too common to trace, or whatnot). It's not directly part of the murder trick so it not even considered. The explanation of why the other incriminating box is still there is also quite ridiculous, since the murderer is left alone for enough time to do strike again with a very timely effort involving her leaving the only room of her bungalow (which involves her, the most known and conspicuous person on set, stalk her in plain view for an undisclosed amount of time), but could not find a few seconds to take a walk a few feet away and bury the box in the sand or bushes, flush the poisoned chocolates down a toilet, throw them at sea, just about anything. It's a bit of chocolate and cardboard, not exactly hard to dispose of that in a big set in the wild.

Stupidity: During a shootout in front of a bank, one of the bank robbers lays his shotgun on the trunk of a car and yells "I'm out!" However, he has 6 additional rounds in a shell holder on the side of the gun. (00:35:20)

Stupidity: And the end, after sliding to another world, the group is caught on film by someone in her house. Quinn goes (illegally) into the home to get the tape. There is no point to this. Throughout the series, many people have seen them arrive, or leave, and usually when there's a mix up with one of their doubles, they spend so much time trying to convince people they are in fact from another world but can't prove it. Quinn doesn't even bother to see how long they're going to be on that world first.

Stupidity: After Cory and Shawn fish Mr. Feeny's watch from the septic tank, he suggests they jump into the lake to clean off. Cory protests, reasoning that it's only 20° outside, to which Feeny dismissively tells them to take a sweater. They then reluctantly abide. Someone of Feeny's education should know better than to allow them to jump into a freezing cold lake. They could both get hypothermia, and they're all currently isolated in the Pocono Mountains with no nearby medical facilities.

Stupidity: Considering he had a watch on in nearly every other episode, the Professor did not have his watch in this episode where they had a rescue deadline time (11:00) to be picked up along with the two Russians. Even if he forgot to put his watch on, he definitely would have paid attention to what time it was and got everyone to the location well before 11:00 to guarantee the rescue. Instead he relied on Gilligan to come up with the time which failed (an earlier submitted entry explains that part).

Stupidity: When Kellin is hit with the neurolytic emitter, it erases her memories of the outside world. However, the effects aren't immediate and take some time (enough to get her to sick bay and have time to talk to Chakotay). However, she spends her time telling Chakotay to help her remember their relationship, etc. when her memory is gone instead of just making a recording of herself describing the relationship and her feeling which can then be shown to her after her memory is gone. She might not believe the recording, but seeing herself discuss the situation would be better than just relying on Chakotay (who will soon be a stranger she never met) telling her something so unbelievable.

Julia Gets Her Head Stuck in a Fence - S4-E8
Stupidity: Once he decided to finally saw into the banister, all Anthony had to do to get Julia's head out was to saw through one of the thin posts on either side of her head. Instead, he saws through an enormous section of the staircase, later causing the governor to accidentally fall through. If he didn't realise that, one of the other designers, all who were looking on, should have. It's a lot to presume they all would have been that careless just for the benefit of a sight gag.

Stupidity: On 9/12/05, during Eve's trial, her sister Liz stood up in the courtroom and began a diatribe in which she discussed subject matter relevant to the trial. Ethan then told Eve that this had harmed her chances. Why, then, didn't Ethan ask for a mistrial? A prolonged outburst like that is a classic example of something that would precipitate a mistrial.

Beyond a Reasonable Scout - S5-E3
Stupidity: Phil the Scout ties a rope to Mikey's see-saw end's handle to lower Gus down without hurting him. Couldn't Mikey just climb off and hold the see-saw down with his hands and lowered Gus's end down slowly?

Stupidity: When Mac and Lindsay are reconstructing the stab wound found on their victim on their pig specimen, a couple of the weapons they use are long, thin knives; since they obviously don't match the circular wound, Mac at the very least would know those could be excluded by default.

The Forecaster (No. 163) - S4-E10
Stupidity: Farnsworth tells Charnquist they've been compromised by a girl listening in on their phone calls and that Charnquist needs to take care of it. He is able to identify the girl, elude FBI, tries to burn his apartment down, is able to gains access to Maggie's apartment and knock out Aram in order to kidnap Maggie. He's a killer who works for someone who has arranged dozen of murders, and knows "take care of her" means kill her. There is absolutely no reason for Charnquist not to have just killed Maggie, Aram, and Fiona. He had opportunity and he ends up killing 3 cops in order to kidnap her and kidnapping Maggie would not have solved anything.

Stupidity: After talking to the bartender, Calleigh goes back the lab and talks to Caine, and he wonders if they got a false positive from the vic's blood alcohol. Calleigh then gives a detailed description of how that could happen; Caine already knows how (obviously this was done for the audience, to explain it, but in the context of the show, it makes no sense).