Continuity mistake: When Batman is fighting some goons right before his boomerang is stolen by a poodle, one of the goons attacks him with a metal pipe, which both opponents take hold of in one shot. Batman then delivers a blow to the assailant, the view shifts further away, and we can see that neither Batman or the goon have the pipe, and it is nowhere on the ground nearby. After this, Batman turns to his right to defend against another goon and we see another enemy coming at him from behind, but after the view shifts to another shot and then back to Batman, this enemy is nowhere to be found.
Continuity mistake: In the scene where the Batmobile diagnostics detects a foreign object, it shows it being located approximately to the front-left of the windshield. It is also a 2D plan view. Yet Batman automatically knows it is BELOW the car and punches through the floor directly beneath him, which is nowhere near where the Batmobile detects it. (01:21:35)
Continuity mistake: When the baby basket is floating through the sewers, there are shadows but no lights, except for one scene where the lights are under water.