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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.
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Claudia and the Secret Passage - S1-E8
Stupidity: The fact that Kristy found the ring that was missing for 40 years just sitting on a windowsill in the secret passage makes no sense; Dawn and Claudia were just by that window earlier in the episode in broad daylight.
Suggested correction: We don't actually see where Kristy found the ring; it was dark, and the girls were chaotic.
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Stupidity: The fact that the young mother in the hospital would give Janet (a total stranger to her) her baby to watch while visiting her husband in a different area is completely unreal. Nobody would really ever just give their baby to a stranger like that and leave. In addition, Janet took the baby into Jack's room for quite awhile.
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Stupidity: The Kramden's door opens out towards the hallway. Yet anytime they need to block the door for protection, they put furniture up against it. That would serve no purpose, even with that cheap slide lock they have. The landlord or criminals could just open the door and push the furniture out of their way.
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Girl Trouble / School Dance - S3-E18
Stupidity: Girl Trouble: Arnold somehow does not see the huge pile of glue that Helga put on his chair before sitting down. (00:03:14)
Suggested correction: Plenty of people don't look before sitting down. I once had someone put a pin on my seat in school and I didn't see it.
I can understand one not catching a small pin on their seat (or clear coloured glue). In fact, that is a pretty common prank. The thing is, Helga put a whole bunch of white glue on Arnold's chair, something so blatantly visible, unlike the other stuff I mentioned. It's just strange to me that Arnold wouldn't see something like that before sitting down in his chair. This also goes for my other entry that you added the same correction for.
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Stupidity: When Richie and Fonzie swap clothing and walk in for The Duel with the Frenchman (both with faces covered to conceal their plan), the whole audience watching The Duel gasp and are all surprised to learn they switched places. But, before the switch was revealed, Richie (as Fonzie) walked in with a nerdier style walk and Fonzie (as Richie) walked "cooler" and looked much more in shape. Also, the head covering Fonzie wore was sheer and you could still see his face, but everyone was STILL fooled.
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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.
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It's Only Rock and Roll - S3-E11
Stupidity: When the gangsters show up at the house Pam and Dak Hampton are hiding in, Pam is captured. Dak then attempts to flee by running out the front door. What a dumb move. No surprise that he got captured as well.
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Stupidity: The whole episode revolves around Adam bringing his girlfriend Emma to his parents' house to meet the family, but problems start to arise when Emma's sister begins texting Adam pictures of her in her underwear. Adam is extremely bothered by this and attempts to make sure Emma doesn't find out. When everyone is at the dinner table, Adam decides to leave his phone out on the table even whilst he continues to receive texts from Emma's sister and the family begin to comment on it. If Adam was so concerned about Emma finding out about the texts, he could have easily turned off his phone and put it back in his pocket, but instead decides to leave it out on the table and switched on, only drawing more suspicion from Emma. Even when the little girl arrives later and asks to play with his phone, Jonny reaches out to grab it, but all Adam does is take the phone off the table so Jonny can't reach it, and then immediately puts it back on the table again.
Suggested correction: Adam knows Jonny is joking with him, as he usually does. As for Katie taking his phone he didn't expect her to. They have all seen Adam's reaction when getting the messages and he is trying to cover something up. Doing anything to prevent anyone seeing his phone more would arouse suspicion. Personally I don't understand why he didn't just explain that Emma's sister has been sending him pictures and ask Emma to talk to his sister. He didn't do anything and loses someone he liked for no reason.
I was mostly referring to the scene where they are sitting at the dinner table BEFORE Katie arrives. Despite the fact that he kept receiving texts from Emma's sister and was growing more concerned and everyone begins to comment on it, all he does is put it back on the table, switched on, ready for another text to come through, which makes everyone further suspicious. There is no reason at all why he couldn't just turn off the phone, put it back in his pocket, and lowered suspicion.
A better idea would be for him to have told Emma after it happened the first time. I'm sure that saying "your sister just sent this to me for some reason. I'm quite uncomfortable. Could you please ask her why she's sent me this?" would have sufficed. He creates bigger issues by denying anything is happening.
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Stupidity: Al tells Peg to hide the meat and cheese tray from Bud and Kelly. Obviously you need to refrigerate meat and cheese yet Kelly says I swear I smell cold cuts. Do we have any? Al and Peg both say no. They both have to see it in the fridge every time they open it.
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Stupidity: When Eddie finally finishes installing the VCR and it explodes, they get a man out to repair it. However, Eddie had previously told Richie that he'd stolen 60 VCRs; 17 in the living room and another 43 in the attic, so they could have used one of the other 59 and saved themselves a crate of Malibu.
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Stupidity: When they are conferring before surgery everyone is keeping scrub except for Avery who has his arms crossed. Shortly afterwards you can see him look around at all his co-stars, realise he screwed up and try to casually raise his arms. (00:15:00)
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First Kiss - S1-E2
Stupidity: When Jeff Malone leaves the sandwich shop, he leaves the sandwich on the table. It would have been very easy for them to tell what was on the sandwich without needing to wait for Max to get home to recreate it. (00:02:41)
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There is Nothing Like a Nurse - S3-E10
Stupidity: Hawkeye and Trapper park a jeep over a foxhole to trap Maj. Burns in it. While it is certainly possible to trap somebody in a hole with, say, a sports car, an off-road vehicle like a jeep is particularly unsuited for the task - the chassis has so much ground clearance, even a quite fat man could squeeze out past it. You can even see the gap when the camera cuts to Major Burns screaming "Let me out!" (00:18:10)
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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.
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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)