Plot hole: Zi Juan tells the rest of the group when they are in Shangri La that she will take the first watch at the entrance and guard against the emperor getting in. A few shots later, she then decides to have a conversation with her daughter nowhere near the entrance, and now with no-one guarding, means he gets in unchallenged.
Suggested correction: A character briefly leaving their watch to deliver important information as Zi Juan was doing isn't a mistake, and it's definitely not a plot hole, since it in no way contradicts the movie's logic or creates a hole in the narrative. At best, Zi Juan was being a little foolish leaving her watch, but a character being a little foolish isn't a "movie mistake." After all, people make foolish choices all the time in real life. Plus, as demonstrated by the movie, it doesn't really matter anyways - the Emperor's powers are back, so she wouldn't have been able to stop him even if she had kept watch.
