Continuity mistake: When Regina's father, Henry, tells her about Rumplestiltskin, he refers to him as "someone Cora knew before I met her." However, "The Miller's Daughter" establishes that Cora first met Rumplestiltskin while she was locked up in King Xavier's palace, after meeting Prince Henry when she delivered the flour and at the masquerade ball. (00:10:45)
Continuity mistake: When Regina is standing by the tree with Daniel, as she says "Have you not seen her magic?" Rocinante, Regina's beloved horse, is standing next to them. In the following wideshot, Rocinante is nowhere to be seen, and there was not enough time to move away from them. (00:08:05)
Continuity mistake: When the Mad Hatter and The Evil Queen are in the portal of doors, on the left side of the mirror, there's a door with green curtains. The design of the curtains changes between wide shots and the shot where they enter Wonderland. Most notably, in the wide shots, the curtains have brown edges, but when they are standing in front of the mirror, the edges are green. (00:15:55)
Continuity mistake: When David is talking to Kathryn in their bedroom, after Kathryn says "It's also been hard on me", the number of buttons that are buttoned on David's shirt keeps changing between shots, which can be seen from the way the opening at the top of his shirt keeps changing in size. (00:34:50)
Continuity mistake: In the scene where Morraine is conscripted into the army, as well as the scene where the knights find Rumplestiltskin and his son on the King’s road, Rumplestiltskin's hand repeatedly moves up/down his staff between shots. The same thing happens to Baelfire in the scene where he and his father are preparing to leave for the Duke's palace.
Continuity mistake: When Emma walks Henry to school, as they exit Granny's, the clock tower building is behind them, and they are walking away from it. But when Henry says "They don't know. It's a haze to them", the clock tower building can be seen on the other side of the street, and they are walking next to it. (00:12:35 - 00:13:10)
Continuity mistake: When Regina casts aside the guards at Snow White's wedding, one of the guards drops his sword on the floor. In the following overhead shots, the sword has vanished. This is best seen when she turns around after saying "I shall destroy your happiness, even if it's the last thing I do." (00:02:45)