Jackie Chan himself filmed an explosion scene. When the fiery police car came sliding dangerously close, the crew jumped out of the way and tried to pull Jackie out of harm's way. But Jackie yelled, "No! Don't run!" and continued filming what turned out to be a spectacular piece of action.
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.
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
She thought they wouldn't have enough time to defuse the bomb, so she wanted to let the bomb explode when Jackie Chan's character was gone so he wouldn't die.