Revealing mistake: In the first shot of the scene where Emma and the others arrive in Storybrooke in their cars, on the left side of the screen, you can see a sign behind a branch. It says "Steveston Museum and Visitor Centre." Steveston is the name of Canadian town which doubles as the town of Storybrooke on Once Upon a Time. (00:07:00)
Revealing mistake: After the Custos's house has been broken into, the next day, the Custos takes a key out of his jacket pocket, unlocks a drawer and takes out a pile of bound papers. When he closes the drawer, he doesn't take the key out of the lock, but he pantomimes his hand returning the key to his pocket.
Single Point of Failure - S1-E2
Revealing mistake: Walter accesses code on the sick girl's laptop to trace the source of the virus - aside from the fact that the code comes straight up a fraction of a second after his hands even touch the keyboard, the code displayed in the black window is for a set of traffic lights, with lines like "Walk/Dont_Walk" and "Green_Arrow/Yellow_Slow." (00:08:10)
Chez Mammy - S3-E15
Revealing mistake: When Cathy and Gaston return to the house to find Betty, Father Damien and Annette Curtain high from the chocolate brownies, she asks where Mrs. Brown is and she tells Cathy that she is upstairs wandering around since she is high. Cathy then tells her to come back downstairs and Mrs. Brown replies a few seconds later saying she is coming back down and flies down the stairs in the chair lift. Before Mrs. Brown comes back down, she can actually be seen sitting in the chair lift at the top of the staircase, from the moment where she tells Cathy she is upstairs to the moment where she says she is coming, waiting for the cue to come downstairs.
Revealing mistake: Samuel Clemens (Mark Twain) spends a night in North Fork while the wheel of a stagecoach he is riding in is being repaired. Clemens is fishing at a lake and Mark McCain says, "You've caught a fish " Clemens tells the boy to reel in the fish. The boy jerks the rod and pulls the fish out of the water. The fish is obviously a fake which a stagehand had attached to the hook. The fish is motionless and is not even wet.
On the Road - S2-E1
Revealing mistake: As Cassidy, Tulip, and Jesse are trying to outrun a police car, another cop car enters the road in front of theirs with tires squealing. There are tire skid marks On the Road before the cop car enters, indicating previous takes of the same stunt.
Row Row Row Your Boat on a Rocky Sea - S9-E1
Revealing mistake: Dr. Charles reads the patient's chart. Near the bottom, it says, "Is this enough filler? My hand hurts." (00:19:30)
Ghost Plane - S4-E13
Revealing mistake: When Michaela and Jared arrest Cheryl, Jared takes the money out of her bag and you can see the "For Motion Picture Use Only" designation on the bills. (00:32:00)
Revealing mistake: At the end, as Ray's parents walk out the back door, Robert says "extra credit". Look out the door when he says this, and you can see the house in the distance wave as if it were a painting.
Revealing mistake: When Danny is driving Mr. Zhao in his convertible at night, you can really see that the background is a bad fake and since even though Danny is driving with the top down, his hair and clothing does not get ruffled at all by the wind.
Revealing mistake: When Kyle, Elizabeth and Robin are in the truck being chased by Mr. Chiang, in all the outside shots of the truck it is very easy to see that all three of them have been replaced by doubles. (00:09:05)
The Father Christmas Suit - S2-E11
Revealing mistake: When Elizabeth is driving Richard's car to the church dressed in the father Christmas outfit with Hyacinth you can see that the handbrake light is on while the car is supposedly being driven.
Revealing mistake: A runway model drops dead. Linda runs over and checks her. The model blinks, and Linda announces she is dead. (00:06:20)
Revealing mistake: After the flashback to when the girls first met Cece at The Brew, she looks at them through a window outside when she leaves. If you look closely at Cece's hair, you'll notice a green glow, revealing that she's on a green screen. This explains why the image of the girls through the window doesn't look quite right. Cece is also wearing a different dress.
The Vision - S4-E12
Revealing mistake: Two oarsmen (or rowers) in Ragnar's boat, the first in front of us and the second from the back, pretend to have an oar but have none. (00:38:35)
Revealing mistake: After Sam shoots Spencer with her blowgun, she lands on the ground after jumping from the ceiling. During this shot, you can easily see that it is a stunt double.
Pilot: The Spirit of Christmas (Jesus vs. Santa) - S1-E1
Revealing mistake: Each time Jesus turns his head to speak to the children when he is beating Santa Claus, he has two left arms.
Revealing mistake: When Toby announces that he's moving to Costa Rica, he gets up and goes to hop the fence. He moves out of frame and when the camera goes back to him, he's been replaced by a stunt double, which can be seen as the double's face is visible after he's scaled the fence. (00:17:15)
Revealing mistake: In a recent episode (April 08), Lloyd referred to Steve as Simon during a conversation in the Rovers. Simon happens to be Steve's real name. Oops.
Crossroads - S1-E5
Revealing mistake: When Easy is paddling across the river to aid the British soldiers, there is a shot where the person closest to the camera (Bull Randleman) appears to be rowing, but there is nothing in his hands.