Corrected entry: The voices were added to the movie later which is why half of the time the voices don't match up to their mouths.
Correction: To add to the other correction, the actors all spoke their native tongues during filming. Hence some were speaking English and the dubbing looks more-or-less natural, whereas others spoke Chinese, and thus look noticeably dubbed.
Corrected entry: Why is Elaine so suddenly friendly towards Jackie at the end of the film, when she boards the hovercraft? Why is she even there? And most importantly, why is her hair so short?
Correction: Elaine is friendly towards Keung (Jackie Chan) because he basically put an end to the mobsters who destroyed her supermarket, and he invited her for a ride to see up close the damage he was going to do to the rest of the remaining mobsters with the hovercraft.
Corrected entry: When Jackie is fighting the gang at their place, he hits someone over the head with a glass bottle. The noise it makes is metallic.
Correction: When Jackie is at the gang's place, he hits a member with a glass bottle, which does not break and makes a cartoony "CLANG/DONG!" sound. This is deliberate and not a sound editing mistake, but rather for comical effect. It does sound out of place however, and comes across as a sign of poor editing.
Corrected entry: When Jackie is driving the Lamborgini and then turns it into a 180 in the first shot the ground is covered with sand to help the car spin. Then in the next scene there is nothing.
Correction: I've watched this scene a few times and that is no sand on the ground. It's nothing more than debris.
Correction: This is because the movie is dubbed. Not a mistake.
Mortug