
Deliberate mistake: When the dome is blacked out and blocking Chester's Mill from the sun, there should be no light at all in the forest, yet it's lit as if under a full moon. (01:10:40)

Intermediate Documentary Filmmaking - S2-E16
Deliberate mistake: This episode is meant to be entirely a documentary made by Abed. At the end of the episode, there's a shot where the gang is looking into Pierce's window, except the camera is right in front of the window they're looking through. If Abed was filming this he would literally be right in front of the gang, completely obscuring their view through it.

Kill or Cure - S3-E9
Deliberate mistake: In a previous episode the Seals conducted a vehicle interdiction snatch and grab because the HVT they were pursuing was said to have lived in an apartment building with a lot of security, cameras, doorman, etc. Part of the team in Mexico now goes to the HVT's two story house to find her dead. What happened to the building she was residing in? (00:11:00 - 00:12:00)

Thank You and Good Night - S1-E8
Deliberate mistake: In the Maisels' 1954 wedding reception flashback, Midge hired professional dancers who perform the "Bottle Dance" (where they slide on their knees). This famous dance, often performed at Jewish weddings and social events, was choreographed by Jerome Robbins for "Fiddler on the Roof," which debuted on Broadway in 1964. It did not exist in 1954 but, as an inside joke, while Midge watches, she says, "That's really good. They should do something with that."

Deliberate mistake: Lee's old crew of three are shooting various caliber handguns at Chloe and Lee's sister. Chloe took cover behind a kitchen island. Kitchen islands are made of thin wood, the only piping in them is plastic and some brass/copper. All of those handgun calibers would have penetrated the kitchen island. (00:45:45 - 00:47:00)

Deliberate mistake: When the sewer worker is trying to escape the Lizard, the fast lanes in both directions of traffic are visibly clear for several blocks, which is extremely unlikely in downtown New York. (00:01:10)

The Campground 'Bizarre' Case - S1-E17
Deliberate mistake: The evidence that proves Kindaichi's alibi is the store receipt detailing the time of his purchase. Notice that the year is recorded too, but it reads "20XY." (00:12:40)

Deliberate mistake: When Joey and Jonathan get in Joey's car at Metropolis (just before heading to the police station), the car has headrests. When they get to the police station, see Lance Gessler leaving and then follow him, the car no longer has headrests. Obviously removed so as not to obstruct the actors.

The Secret of the Unicorn: Part 1 - S1-E3
Deliberate mistake: After Francis Haddock kills Red Rackham, he lights a fuse to the explosives. The fuse that was lit is only a foot long, yet he is somehow able to climb out the ship without anyone noticing, get into a boat and swim all the way to land before it explodes. At a foot long it would have exploded in 10 - 15 seconds, all of that would taken at least 10 minutes. (00:18:45)

Deliberate mistake: They show footage of Max and Larabee scouting out the entrance to a bank. This same footage was used in the earlier episode "The Treasure of C.Errol Madre".

Deliberate mistake: When Fluttershy is telling off the cockatrice, her back legs and her wings turn to stone. But when she gives it the stare and the camera is right in her face her wings are outstretched.

The Stadium - S1-E8
Deliberate mistake: The Korean lady's Mini-Uzi never runs out of ammunition, and she's spraying it at full-auto. A Min-Uzi's cyclic rate is 950 rounds/min. One long squeeze of the trigger and the weapon's dry. Same goes for all the other weapons like the M4 carbines being fired on full-auto, they have the infinity ammo cheat code going here.

Deliberate mistake: The ghosts often walk around furniture even though it was established that they can walk through solid objects.
Suggested correction: Just because they can walk through solid objects doesn't mean they have to. They were used to walking around things in life so just carry on doing so as a reflex action. They often use open doors too, only walking through walls when it's more convenient for them to do so or the doors are closed.

Deliberate mistake: When Thomas goes by the level crossing, a close up of Thomas is shown but it's the same footage from season 1, only flipped. Because of this, Thomas' number is mirrored.

The Hit Car - S1-E3
Deliberate mistake: When Starlet asks Ralph if he believes that stars can predict his future, Bill tells them to put a dimmer on the googoo eyes because of the killers on their tails, and the two shots facing Bill are flipped. (00:14:40)

Deliberate mistake: At Pete's diner, the owner puts the tray down, and instantly glasses appear in front of the 5 patrons. (00:02:50)

Deliberate mistake: When Roy and Moss are in Jen's office talking about her slipping up, the computer monitor disappears from her table in the wide shots so you can see the actress.
Suggested correction: It's there the whole time. It's a thin monitor and it lines up with Roy's leg, so it might have been hard to see.

Deliberate mistake: Inside the home that has been infested with Evil, the state police confront a possessed girl who attacks them. After some futile gunfire, the possessed girl is still standing. The female officer goes for her backup gun, which for some reason is a small over-and-under Derringer (meaning she has two shots maximum). She ends up firing the Derringer five times in just a few seconds, with explosive damage and without reloading. Director Sam Raimi probably staged the 5 gunshots on purpose, knowing that a two-round Derringer was a ridiculously-limited piece of firepower. Raimi probably did this as a tongue-in-cheek tribute to Ash's bottomless double-barrelled shotgun from Evil Dead 2 and Army of Darkness.

Deliberate mistake: When the young kid breaks out of Jeff's apartment, the ladies freak out that he's naked, when he's wearing black underwear. And then shortly after they shriek to police that he was buck naked when he wasn't.

The Last Temptation of Barry Allen, Pt. 2 - S6-E8
Deliberate mistake: There's an awkward moment during Cecile and Kamilla's escape from Bloodwork's minions where Cecile doesn't close the door for several seconds so the cameraman can walk through as they follow them.