Continuity mistake: In the beginning, when Billy is talking to the bum (who later turns out to be Tawny), the bum has a glove on his right hand. When he reaches his right hand out to Billy and Billy gives him a subway token, there is no glove. It's back in the next shot.
Continuity mistake: After RVD is shot by the lone motorcyclist he goes home to take care of his wound. You can see that he was shot in his LEFT shoulder. When he goes to the bathroom and takes off his shirt, the wound is on his RIGHT shoulder. After bandaging up his wound, he finds his wife bound and gagged and his daughter has been taken. He goes out to the garage and you can see his LEFT shoulder is now bandaged. (00:58:50 - 01:01:55)
Continuity mistake: When one of the robbers is walking away with 4 bags stuffed with money, you can see a large stack of money bills sticking out of the bag. In the next shot the bills are gone. (01:04:40)
Continuity mistake: Throughout the motorcycle/police car chase they used two different motorcycles made 50+ years apart and just painted them both black. One is a 1940s Harley Davidson with a springer front end and the very recognizable horn below the headlight, and the other is a late 1990s (at the oldest) cruiser with a front end that's completely different in every way.
Continuity mistake: At the end when Walter Weed comes to the escape car the car is already running, with smoke coming from the exhaust, but then he starts the car when he wants to drive away.
Continuity mistake: Jason spits blood onto Joker's chin which changes spot wise and shape wise by the next shot.
Continuity mistake: During the last scene, the strands of hair that Edgar has running down his face/right cheek are over the top of his head during some shots. Edgar is holding a book between both hands, so not moving the strands himself. (01:16:19 - 01:16:55)