Other mistake: When Jackie is singing in the restaurant and the evil guys tell everyone to leave, there is an old man on the stairs in the background. Two shots later the stairs are shown again and the man is gone. He was walking too slow to have gotten off of the screen that fast.
Other mistake: When Fei Hung and his father return home near the beginning of the film, the father walks in the background with a servant. Fei Hung does something with the suit he is wearing. Look at what he is doing closely and you will see that he seems to be "unzipping" something. There isn't a zipper or anything for that matter where his hand is.