Continuity mistake: When Daryl is driving the hospital van, it shows that he is going to land upside down, on the vehicle's roof, when he drives off the parking garage. In the next scene, the vehicle lands on its wheels, as if it has done a complete front flip. (00:30:00)
All Hell Breaks Loose (1) - S2-E21
Continuity mistake: Before the Roadhouse fire, Ash and Dean are talking on the phone. Ash looks at his watch, on his left hand, it says 8:10, and has a black dial/face. As Dean and Bobby go through the rubble, Dean identifies Ash by his watch. Still on his left hand, it is now upside down, evident by the crown of the watch (used to move the hands of the watch) which previously facing his hand, is now facing his elbow. Also, the dial/face of the watch is now silver instead of black. This is a different watch, and was inadvertently put on the burnt arm upside down.
Factual error: In Oregon and New Jersey, state law requires that a gas station attendant pump the gas. Romero pulls into an Oregon gas station and encounters a nosey person. They are both pumping their own gas.
Chapter Two: The Weirdo on Maple Street - S1-E2
Factual error: When Chief Hopper and his fellow patrolman are standing over the lake, Hopper has a radio on his belt. The radio is a modern Motorola walkie talkie and at least a decade newer than it should be.
Other mistake: When McNulty uses the stopwatch to rob a bank, he goes through a small wooden door and past the employees. With time frozen, the small door should have stayed open but immediately swings shut.
Visible crew/equipment: When Mulder and Scully enter the abandoned mine through a doorway, the viewer can see at right in the distance a number of people sitting on a wall, and one crouching in front of the wall with what looks like a dog. They are sitting still, but there is still movement there. (00:16:00)
Confinement - S2-E5
Continuity mistake: Ruby asks Ash where the the Kandarian Dagger is. He says that it was confiscated by the police. In the previous episode, she had and used it, and they have not interacted in the intervening time period.
Continuity mistake: Duke is wearing an extra shirt, and his hair is longer then it was, despite continuing the scene from the end of season 2.
Continuity mistake: The shots of Doran from his left rear shows him a couple feet away from the wall while frontal shots show him backed up against the wall.
And Those We Left Behind - S4-E6
Plot hole: The very ending scene where Peter (in this version died in the ice as a boy so Walter's wife never met him) takes off some of the dust covers then picks up a toy airplane. The toy airplane he got as a child from ... Walter's wife when she was trying to placate him in an earlier episode for trying to run "home". This toy airplane wouldn't have been his as a child in this version of the universe. (00:42:00)
Cold Ground - S1-E6
Continuity mistake: When Sookie is eating Adele's pie, the amount of pie on the fork keeps changing between shots. (00:41:25)
Revealing mistake: When Elsa is waiting in the lobby, she's wearing a dress which shows her normal, not wooden legs. It's very apparent when she is crying on the floor.
Other mistake: When Theo is thinking back to when Steve offers to share the royalties from his book, Shirley is heavily pregnant with her daughter. However, on the table next to Theo, is a photo of Shirley's son and daughter, as they are in the present.
Continuity mistake: Near the start, the camera pans out to see the dome now covered in a layer of black. Outside of the dome you can see nice green fields, a small forest area, little houses and everything looks rosy. However a few episodes back the military launched a MOAB (mother of all bombs) and and the surrounding area was wiped out completely. (00:05:50)
Suggested correction: The entire left side of the dome is where the bomb blew up. Now if you watch back when the bomb hit the dome, picture the lake being to the north on the map. When Joe and Norrie were looking for Ange, and they were on the bench when the bomb hit, SW in the scene is a pretty close point to when they show the aerial shots of the dome.
Continuity mistake: 1-13 "Mourning After": The blood Ashe smears on her face changes its pattern and consistency several times as the shots change. (00:36:00)
Continuity mistake: When Alicia is cleaning up Nick's vomit, she removes her gloves. When the angle changes, she starts removing them again. (00:24:45)
They Have Been, They Are, They Will Be... - S1-E3
Continuity mistake: While Tony Vincenzo is eating, his butter knife instantly turns into a fork in the next shot.
Factual error: At the beginning of the intro, the narrator says that the only way to resurrect a vampire is with a sacred rite that can only be performed once a century when the moon is in the eighth house of Aquarius. In Astrology, the eighth house is Scorpio.
Factual error: Nick tells fellow vampire Aristotle, "You still owe me for that time at the Battle of Hastings." Nick was brought across in 1228, or so the intro told us every week. The Battle of Hastings, as any British school kid knows, was fought in 1066, over 100 years before Nick's mortal birth. (00:29:30)
Audio problem: 1897: Quentin challenges Barnabas by pulling a decorative sword from a wall display and pointing it at his throat. Unfortunately, the display wasn't all that well attached to the set wall. Though the camera pans away, you can hear a loud clunk as the piece falls, followed by the loud crash of shattering glass as it strikes and breaks a table lamp. You can also see the actors struggling very hard to keep straight faces as they continue with their lines.