Jackie dries very quickly after exiting the water.
A dragon dance is never performed in a Chinese funeral, nor is the letting off of fire crackers - they are for celebrations, not for mourning.
After Jackie meets up with Annie with the security guards at the elevator, the security guard talking on the walkie-talkie says that they are on the top floor, but after Jackie pushes both guards into the elevator, you clearly see the elevator going up, clearly indicating there is at least one more floor.
In the snowboard scene, all the close-ups of Jackie show him snowboarding right-handed, but in all the long shots - including where he jumps onto the helicopter skid - he snowboards left-handed, with the opposite foot in front, suggesting that the long shots are of a stunt double.
When Jackie climbs out of the back of the van near the beginning of the film the tailgate bounces as he closes it, revealing it was rigged in the unlatched position to allow him to open it from the inside.
When Jackie gets on the snowmobile for the first time we see Russian signs all around him. Yet a moment later he drives by some signs very much in English.
In the ski chase scene when the helicopter drops its second load of soldiers, the one on the right drops off, stumbles, and falls just before the scene cuts away.
Tsui's name is mispronounced throughout the English dub of the film. The correct pronunciation is "Choy".