The Thing You Love Most - S1-E2
Continuity mistake: When Emma arrives in Storybrooke in "Pilot", the sign on the clock tower is a green house-shaped structure, and there are six small boarded up windows on The Tower. They are still there when Henry is watching the town clock from his window in the evening at the end of "Pilot", and in the beginning of this episode. However, the following morning, the sign on the clock tower is a white rectangular sign, and white signs are covering the windows. The clock tower remains this way for the rest of the series, with two exceptions: When Regina looks out the window and sees the purple cloud approaching in "A Land Without Magic", and when the Shadow flies through town after being released in "The New Neverland", the green plaque and the windows can be seen on the clock tower. (00:00:40 - 00:01:15)
Continuity mistake: During Emma's date with Hook, the waiter is carrying a basket of food. As Will bumps into him, the waiter is just about to put the basket on the table, but in the next shot, it is already sitting on the table.
Other mistake: In the end credits, Michael Coleman, who plays Happy, is wrongly billed as "Micahel Coleman." (00:41:00)
Revealing mistake: When David is letting Henry drive his truck, there is a close-up of Henry, followed by a wide-shot of the car where the tires are screeching, and you can see that the one who is actually driving is Jared Gilmore's stunt double. (00:30:15)
The Heart is a Lonely Hunter - S1-E7
Continuity mistake: As Emma exits the crypt, in the wide shot, Regina's left hand, holding the flowers for her father's grave, is at her waist. In the next shot, her hand is down by her side, before she brings it up to show the flowers. (00:33:35)
True North - S1-E9
Continuity mistake: As Emma returns to the apartment, Mary Margaret is folding clothes on her bed. As she sees Emma, she's holding out her arms, but in the next shot, her arms are down by her side. (00:37:05)
Continuity mistake: When Rumplestiltskin rips out Milah's heart, Killian catches her as she falls down. In the first shot, the back of her head is resting on his shoulder. In the next shot, her position has changed, and her head is resting on his arm. (00:28:10)
Continuity mistake: Before the duel, as Rumplestiltskin says, "Sorry, but killing a man with his own sword was just too delicious to pass up", Killian's right arm is bent. In the next shot, his arm is down by his side. (00:17:25)
Revealing mistake: As Killian Jones and Rumplestiltskin duel, there is an overhead shot of them fighting, and in the next shot, you can see that Robert Carlyle and Colin O'Donoghue have been replaced by their stunt doubles. (00:17:35)
The Thing You Love Most - S1-E2
Factual error: This episode takes place the day after Emma decides to stay in Storybrooke and time started moving. According to "The Stranger" and "Selfless, Brave and True", August woke up in pain in Phuket on October 24, 2011 at 8:15am, the exact minute that Emma decided to stay in Storybrooke at 8:15pm. Since Thailand is 12 hours ahead of Maine's timezone, this means that time started moving in Storybrooke on October 23, and that this episode takes place on October 24. During Regina's conversation with Emma in her office, she says, "Did I know that my son comes to my office every Thursday at precisely 5pm so I can take him for dinner before his therapy session? Of course I did." However, October 24, 2011 was a Monday. (00:30:05)
Factual error: In "What Happened to Frederick", Kathryn learns about David's affair and confronts Mary Margaret at school (after taking her anger out on Regina), where students and teachers are milling about. Later, she apologizes to Regina for "what happened yesterday", whereas Emma, earlier that day, seeks out Henry at school. Kathryn leaves Storybrooke the same day, and mysteriously disappears. According to Kathryn's phone records in this episode, she disappeared on a Sunday. However, the day she left, and the day before, was a school day. In the U.S., school classes are not in session during weekends. (00:38:25)
Continuity mistake: When Mary Margaret and Emma are walking down the street, as Mary Margaret says, "This is the best I can do", she begins to walk past the corner of a building. In the next shot, they begin to walk past it again. (00:05:15)
What Happened to Frederick - S1-E13
Revealing mistake: At Granny's, when Emma and August ride off on the motorcycle, you can see that the one driving is actually Eion Bailey's stunt double. (00:21:45)
Continuity mistake: In Pinocchio's home, when Jiminy Cricket pops out of the cuckoo clock, a navy officer doll can be seen sitting on a table as Geppetto goes to release the cricket. In the first shot, the doll is perpendicular to the chair next to the table, but when Jiminy says, "It's okay. He meant no harm", the doll has turned around 90° and is parallel to the chair. After the Blue Fairy shows up, the doll is back to its original position. (00:12:30)
Continuity mistake: After Emma gives Hook mouth-to mouth, her left hand keeps changing position: Most noticeably, as she whispers, "Hook, come back to me", her hand is on his chin. In the next shot, her hand is resting on his chest. (00:11:50)
Continuity mistake: In "The Shepherd", Kathryn is showing David their house, and you can see that the street number on the Nolans' house is 244. In this episode, when Emma is looking at Kathryn's phone records in the evening, the phone records list her address as number 4. (00:38:25)
The Thing You Love Most - S1-E2
Continuity mistake: When Emma is wearing the red dress in "Pilot", she has a mole on her chest. In this episode, which takes place two days later, when she's in her white tank top, the mole is gone; this is best seen when Graham is taking mug shots of Emma, and she says "He's terrified of her, like everyone else in this town." This is probably due to the fact that in real life, Jennifer Morrison has had several moles removed from her body. However, there was no time for Emma to do the same, and even if there were, she'd have a fresh scar or stitches. (00:20:30)
We Are Both - S2-E2
Revealing mistake: When Regina is trying to escape on horseback, as she says "Come on, Rocinante, go!", you can see that the one who's actually riding the horse is Lana Parrilla's stunt double. The stunt double's face can also be glimpsed when Regina is caught by the tree branches, and when she drops to the ground. (00:05:20)
Continuity mistake: In the scene where Snow is in Emma's nursery room, trying to convince Charming to talk to Rumplestiltskin, the shots have been flipped. The easiest way to spot this is Charming's scar, which is on the wrong side of his face. (00:10:30)
Continuity mistake: When Graham offers Emma the job as a deputy sheriff, when he gives her his card, you can see two women a few meters behind Emma, walking on the pavement, toward the camera. In the next shot of Emma, only a few seconds later, the women are still walking in the same direction, but they are much further away from her than in the previous shot. (00:16:15)
Answer: He knows who she is because he knows that the fairy tales are true. He was also shown to sneak out to go see Emma or someone else. Sometimes he succeeded, sometimes he didn't. This is how he knew to look for her despite his strict mother.