Revealing mistake: When Snow White and Prince Charming hurriedly make their way through the woods in the beginning of the episode, in the shot where Snow White jumps over a log, you can see the face of Ginnifer Goodwin's and Josh Dallas' stunt doubles. Josh Dallas' stunt double can also be seen as Snow and Charming are running thought the woods in the previous shot.
Revealing mistake: After Mr. Gold's group leaves Mary Margaret's apartment, in the wide-shot where Mr. Gold asks Cruella and Maleficent to follow Regina, a direction sign pointing to a shop called "Steveston General Store" can be seen on a building. Steveston is the Canadian town which doubles as the town of Storybrooke on Once Upon a Time. (00:14:30)
Chosen answer: Even if one can see the future, it can be somewhat vague and left open to interpretation.
raywest ★
He can sees the future all jumbled up. It is like a puzzle, it is hard to put together, but even when he does put it together it is not set in stone the future can change.