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: The last remaining Xindi, in desperation, attempts to release the virus over the fan, despite the virus not being fully ready. However, it seems the only reason he didn't release the virus at that time was he had to seek cover from Archer and T'Pol shooting at him and to start shooting back at them. However, he had plenty of cover from the rooftop stairwell, which was right next to the fan, and he had enough time to dump out the contents over the fan.
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)
The Prison Prep School Murder Case File 5 - S1-E14
Stupidity: The plot could work only if everyone part of the trip were completely silent during the day; even walking through the empty corridors to go from one class to the next at the top of the hour would have inevitably tipped the other group that there was someone else nearby. Some even scream or freak out hitting things.
Stupidity: Paulie and an associate just killed 2 drug dealers or stash house guards, and they are rummaging throughout the apartment touching appliances and other surfaces without any gloves. Paulie was previously arrested and did time so his fingerprints are on file. Paulie also used a knife to stab one of the Colombians without any gloves on, and he just left it in his body. The police would have no problem linking him to this crime within a week after forensics did their sweep. (00:03:00 - 00:04:17)
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.
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?
Stupidity: In the original, the knight of the Phoenix suddenly appeared during the arena fights interrupting the show and stealing the Gold Cloth. In this remake of the saga, Sienna/Saori Kido leaves the arena by plane during a bombardment that occurs way before Nero/Ikki arrives to steal the Cloth. There is no reason why she would fly off in her VTOL without bringing the Golden Cloth with her, then (there's a lot of time for that). Instead she leaves it for the 4 Saints for them to "protect it", against a whole army and on foot in the middle of the desert.
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.
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.
Stupidity: Throughout this entire show, there is almost ZERO explanation of how, in such a small town, murder, assault, battery are committed by the club with no mention of HOW they're able to do so. This is with DNA, a barrage of ATF agents (in the beginning), and let's assume a forensics lab in the entire state. Has anyone seen forensic files? I mean come on, in the 80s in cities 100+ larger they were able to solve crimes.
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 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.
The New Original Wonder Woman - S1-E1
Stupidity: There's much fuss about who will take Steve Trevor back which is resolved via a contest. Why the Amazons don't heal him, if possible, then set him adrift to a safe port is never asked. They did this when Nazis invaded in the two part episode The Feminum Mystique.
All Politics is Local - S1-E24
Stupidity: At the end of the episode, Joey and Melissa are in the kitchen, discussing Melissa's father. A small pot on the stove is very full of broccoli; almost overflowing. It makes no sense that Joey - who is a proficient cook - would be trying to prepare that much broccoli in a pot of that size.
Stupidity: When Clark is trying to sneak Lana out of the house, they walk past the front door in order to go through the kitchen door, where they get caught. It makes no sense to not use the front door. This way Lana is already outside, the whole goal in the first place, should his mom or dad see them. Not to mention the fact that Lana's car is still parked outside and Johnathan or Martha would have seen it, so they shouldn't be surprised to see her in the house.