Revealing mistake: When Sheriff Graham pulls in front of Emma in a police car, the big sign on the storefront behind Emma says "Storybrooke Coffee Co." However, as Graham gets out of the car, you can see a circular sign on the side of the building, which says "Steveston Coffee Co"; Steveston is the Canadian town which doubles as the backdrop for the town of Storybrooke on Once Upon a Time. (00:05:30)
Revealing mistake: When Graham offers Emma the job as deputy sheriff, as he says, "Why don't you think about it", in the background, the name "Steveston" appears on the sign on a business next to Kisamos Greek Taverna. Steveston is the name of the Canadian town which doubles as the town of Storybrooke for exterior scenes. (00:05:50)
Revealing mistake: As Mr. Gold bangs his head on the table after being spritzed with pepper spray, you can see that one performing this action is Robert Carlyle's stunt double, and that the stuntman merely hits the table with his hands. (00:10:20)
Revealing mistake: When Emma leaves the apartment to go looking for Ashley, she and Henry walk down the streets of Storybrooke, toward Emma's car. As Emma says, "Because I know", in the background, you can see a business called Steveston WineMakers. Steveston is the name of the Canadian town which doubles as the town of Storybrooke on Once Upon a Time. (00:14:35)
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.