The first time we see Wing take out his cellphone in a bar, he was holding a Nokia 7610. Next, when he calls his girlfriend's number outside her apartment, he is holding a Nokia 6600. Soon after, we see him holding his Nokia 7610 again. Just as he enters his girlfriend's apartment, he is using the Nokia 6600 again. From then on, he just uses the 7610.
After the bank teller, who was used as a human shield by Joe, is killed, he falls to the ground Moments later, an extreme close-up of Joe firing his gun is shown, yet in the shot you can clearly the bank teller's shoulder in the shot
At the beginning of the movie, a drunk Police Inspector Chan Kwok-Wing (Jackie Chan) is seen failing to get a taxi. When he is sitting on the street, white crosswalk bars can be seen. Hong Kong uses yellow crosswalk bars.
When Chan and his assistant repel down a rope in pursuit of the robber, both their improvised equipment depend on the rope being stretched tight for friction. When the robber disconnects, both of them should free fall. Especially the assistant when Chan also disconnects.
When the detective gives Chan his Glock pistol towards the end of the movie, he takes the magazine out and lays it on the table next to the gun. Glock magazines have holes in the back of the magazine so you can see how many rounds are in the magazine, and it is possible to see that this magazine is empty except for the one round visible.