When she has her Homecoming dress on before the battle you see Wendy clearly with pink high heels on. Then they show the fight scene and you see her with pink flats. Then she goes up to kick, and she comes back down, and she has on her high heels again.
In the scene where Shen is seen walking down the road as he tries to hitch a lift, you can see all the cars are driving on the right side of the road. However, in some background shots you can see the traffic moving on the left side of the road as it is supposed to in New Zealand where the film is shot.
Obvious stunt double for Jessica, during the fight with Wendy.
When Wendy is meditating to re-learn her history, her legs are crossed Indian style. In true Buddhist meditation the legs are placed in full or half lotus position where one or both of the feet are above the legs rather than below.
The museum guard unlocks the door each time someone knocks on it, but is always shown closing it afterward and walking away without locking the door again.