Plot hole: In the lab when Liz makes the slides of her cheek cells and the cells from Max's pencil, the first time she doesn't add stain and the second time she does. If she's going to be a molecular biologist she really ought to learn to apply techniques consistently. (00:07:30)
Plot hole: It's been established that if you die on the property, you remain as a ghost for all of eternity. However, in Season 8, Moira's bones are retrieved and buried in a cemetery so that her ghost can escape and join her mother. However not all the ghost's bones are buried on the property, we know for sure that the Black Dahlia was not buried on the property and it's not likely Tate, Vivian, Ben or some of the others are buried on the property as well so they should not be tied to the house.
Suggested correction: Tate's victims from the school shooting are ghosts who can move between different locations. There's nothing to suggest that the ghost of the Black Dahlia isn't merely choosing to be in the Murder House rather than being tied to it. The same goes for Vivien and Ben, since Violet is going to stay in the house, so might they.
The Amazing Psych-Man & Tap Man, Issue No. 2 - S6-E4
Plot hole: The flashback involves Young Shawn and Gus getting ready to go to a comic book convention, Shawn in costume, with his father's consent. This contradicts the flashback in "Shawn Vs The Red Phantom," where Henry won't allow Young Shawn to even read comic books or play superhero with a towel around his neck.
Over My Head - S3-E4
Plot hole: Daphne was able to hurt Duke because his name appears on her cell when he called, but names only show up on a cell phone if the person's number and name are programed into the phone, and Duke has already said he doesn't know her.
The Monsters are Due on Maple Street - S1-E22
Plot hole: The street sign in the beginning is all wrong: it faces the camera rather than the street where the story takes place. In a typical American city, street signs are almost always placed in the direction of the street they are indicating, so drivers on the other street in the intersection know what they are turning onto or passing. In other words, the story is not set on Maple Street! Maple Street is the intersecting street at the end of the road the story is set on.
The Messiah on Mott Street - S2-E38
Plot hole: No one in Goldman's house finds it at all strange that a mailman arrives at the door with a letter after midnight on Christmas Eve. Nor, a short time later, does the doctor or anyone else passing by at this very odd hour wonder why the same mailman is collecting mail from a street box at dawn on Christmas Day.
Are You...? - S7-E1
Plot hole: It's out of character and against his code for Dexter to kill Viktor at the airport. Airports have security cameras everywhere (you can see one on the ceiling when he is wheeling Viktor into the unclaimed baggage storage), and using the unclaimed baggage storage as the kill room is equally unwise, because any airport employee could walk in at anytime and catch him red-handed. Dexter was caught murdering Travis Marshall by Deb just hours before, so if anything, he should be even more cautious.
The Beacon - S1-E26
Plot hole: Barrows introduces himself as "Dr. Dennis Barrows," and Teddy asks, "What's a doctor?" As the isolated villagers have never heard of doctors, Teddy would have no way to know that "Doctor" was a title/profession and not simply part of Barrows' name. He should have asked, "What kind of a name is Doctor?"
A Deadly Net - S2-E2
Plot hole: S2E2 A Deadly Net Midway through the episode, Sylvia and others in the cast bid people goodnight, offer after-dinner drinks, but the sun is shining brightly and continues to do so for quite a period of time as events continue to unfold.
Chapter Seven: The Massacre at Hawkins Lab - S4-E7
Plot hole: The upside down should be mirrored, i.e. all left is right and right is left. When the team finds a gateway where Chrissy died, they should be seeing a mirror image through the ceiling. Also, all buildings should have been reversed. Directions to get there on the bike would have been confusing and reversed, and when any writing was seen in the upside down, it would have been backward.
Episode #4.1 - S4-E1
Plot hole: When DCI Roz Huntley kills Forensic Coordinator Tim Ifield the crucial piece of damning evidence is her DNA under his fingernails after scratching her arm. Problem being, at the time of his murder, he was wearing surgical gloves. (00:56:40)
Inspector Kenmochi the Murderer File 2 - S1-E20
Plot hole: The brief intermission when Busujima meets the 'killer', or at least the person wearing the hat, does not make sense plot-wise and is merely a dishonest way to trick the audience. It's not even something Busujima tells someone, so it can't be characterized as a 'unreliable narrator' device. (00:18:30)
A Scooby-Doo Valentine - S3-E3
Plot hole: It's never explained how JC Chasez and the Hollywood extras impersonating the gang gained the super strength they possessed to do things like ripping car roofs open or holding up the Mystery Machine.
Plot hole: When the watch is sucked to the island by the magnet, where was the sailor that the watch was attached to?
Plot hole: After Jack's wife disappears for a couple of days, he receives a call from her cell phone from the cab driver who found it. Jack arranges to pick it up from a hotel. After he picks up the phone, its battery dies as he checks it, at 12:13pm. In the next scene with Jack, he's in a bar with the phone plugged into a charger; when it comes on, he checks it - the battery shows 3%, but the time is 9:13pm. He apparently wasted 9 hours when he's in pursuit of his wife's mysterious disappearance before plugging in the phone. A scene later, the time is now just a minute later at 9:14pm but the battery is now charged to 79%. (00:37:25 - 00:40:45)
Plot hole: During Ryder's report, as Bruce and company watch it on TV, the camera suddenly zooms in on Joker standing on a catwalk above Ryder, and none of the crew, especially not the camera man who caught the villain, makes a comment about this. They may have thought the Joker (or rather an impersonator) was perhaps a surprise gag in the show, but since this is supposed to be a serious documentary report, it is still strange that they wouldn't point it out.
Farewell My Beloved Witch - S1-E3
Plot hole: Lupin was captured by chance, and he did not plan for that, nor he seemed to have previous knowledge of Stern's appearance, but he escapes regardless using a Mission Impossible-like perfect mask of him. He also somehow kept his own blazer, tie and shoes underneath the uniform and boots he stole and wore. (00:16:00)
Episode #1.2 - S1-E2
Plot hole: Contrary to any other version (including the novel), here the mastermind behind the murder realises in timely fashion that burning the letter was a mistake, it was not actually part of the plan. With this change, they'd have still all the time in the world to go back to the compartment and get the burnt remains, but they simply do not.
Plot hole: The poison is in the dog collar. Anson gets the poison from touching the collar. Why didn't the dog get any poison from the collar?
Suggested correction: The poison cannot penetrate the skin as dogs don't have sweat glands on their bodies (except on the paws).