Continuity mistake: When David and Rumplestiltskin walk down the streets of Storybrooke while searching for Belle, as David says "There is a difference between literal truth and honesty of the heart", a car is seen driving through the street. In the next shot, it's gone. (00:21:20)
Continuity mistake: When Milah and Killian board The Jolly Roger, as Milah says "Fetch some water", a pirate with a coil of rope around his arm has just ascended the deck and is seen near the steps. In the next shot, he is nowhere near that area (he can briefly be glimpsed as he disappears behind a mast in the lower left hand corner). (00:25:45)
Continuity mistake: Aboard The Jolly Roger, Rumplestiltskin says "Do I forgive you? Can I move on?", while walking past Milah. In the first shot, he is right behind her, but in the following wide-shot, he has suddenly moved to a position several meters away from her. (00:26:40)
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)
The Doctor - S2-E5
Continuity mistake: When the women find Hook under a pile of dead refugees, the amount and position of the dirt on his face changes a couple of times. The scarf around his neck also changes position. (00:01:40)
The Doctor - S2-E5
Continuity mistake: When Emma is questioning Hook while the group is gathered around the bench, the folds in the cloth/bundle lying on the bench keep changing between shots. (00:14:30)
The Doctor - S2-E5
Continuity mistake: When Hook is tied to the tree, the arrangement of the ropes changes throughout the scene. (00:24:40)
The Doctor - S2-E5
Continuity mistake: When Hook is tied to the tree, Emma raises her right hand to her mouth to whistle for the ogres. In the next shot, she uses her left hand. (00:26:45)
The Doctor - S2-E5
Continuity mistake: When Regina is in the stable with Daniel, after she says "No, I won't lose you again", in some shot, she has her hands on his face/neck. In others, her hands are on his shoulders. (00:31:45)
Tallahassee - S2-E6
Revealing mistake: When Hook and Emma are climbing up the beanstalk, as Hook remarks, "First beanstalk?", you can see that Colin O'Donoghue is actually gripping the vine with his left hand, which is covered up by his sleeve; the hand that was cut off. (00:08:50)
Tallahassee - S2-E6
Continuity mistake: When Emma is arrested, she has a flower tattoo on her left wrist. When she's climbing the beanstalk with Hook, in a few shots, her wrist is bare, and you can see that the tattoo is missing; this happens, for example, when she remarks, "You should be used to people not trusting you." (00:09:10 - 00:29:30)
Tallahassee - S2-E6
Continuity mistake: Sidney's newspaper article in 1-8 "Desperate Souls" stated that Emma was arrested in Worcester, Massachusetts in 1996. However, this is directly contradicted in this episode, which shows that Emma was actually arrested in Portland, eleven years before the frame story, meaning that the arrest took place in 2001 (since "Selfless, Brave and True" establishes that Emma arrived in Storybrooke in October 2011, and the frame story of "Tallahassee" takes place a few months later, in 2012; the year 2001 is confirmed in 3-22 "There's No Place Like Home"). (00:17:55)
Tallahassee - S2-E6
Continuity mistake: When Hook and Emma find the skeleton of Jack the Giant Killer, in the close-up shot, Jack's sword is in the skeleton's hand. When Emma remarks, "With that toothpick?", the sword is lying beside the hand. When Emma grabs the sword while being chased by the giant, the sword is back in Jack's hand. In addition, the skeleton's arm alternates between being bent and sticking straight out between shots. (00:23:15)
Tallahassee - S2-E6
Continuity mistake: In the giant's treasure room, there are many giant gold coins near the skeleton of Jack the Giant Killer. The amount and position of the coins repeatedly changes. For example, when they find the skeleton, there are several coins on the edge of a small dais, but when Emma saves Hook from the trip wire, they are missing. (00:24:40)
Tallahassee - S2-E6
Revealing mistake: When Neal is being chased by August, he runs on top of a car before attempting to jump the fence. Just before he jumps on top of the car, you can see that the one who actually performs this action is Michael Raymond James' stunt double. (00:26:40)
Tallahassee - S2-E6
Continuity mistake: When Anton throws the compass to Emma, the compass changes position on the floor between shots, seen from the lines/cracks in the floor. (00:33:45)
Tallahassee - S2-E6
Continuity mistake: When Emma cuts the trip wire in Anton's castle, the surroundings change completely between shots; for example, as she cuts the wire, there is an open chest near her. In the overhead shots, the chest is gone, and Jack's skeleton is missing. (00:33:50)
Tallahassee - S2-E6
Continuity mistake: As Snow and Mulan fight, Snow's pink cardigan gets covered in straws. The amount and position of the straws keep changing during the fight, and afterwards. Also, when Snow tackles Mulan, in the first close-up of them fighting, you can see straws from previous takes on Snow's cardigan, even though she has not come into contact with the ground yet, and the cardigan was perfectly clean in the previous shots. (00:37:40)
Tallahassee - S2-E6
Continuity mistake: When Emma jumps from the beanstalk and hits the ground, Mary Margaret turns her head to look at her. In the next shot, she turns her head again. (00:38:20)
Continuity mistake: At Granny's, when Ruby is clearing tables and Billy startles her, the amount and position of the food on a plate changes between shots. The cup and the napkins also change position on the table. (00:02:35)
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.