Other mistake: Croc's feet are briefly a shade of pink after his sewer fight with Bane.
Continuity mistake: Two-Face's left leg is blue here whereas it was normal in part 1 of his origin episode.
Continuity mistake: When Riddler burns his costume, he's wearing his purple gloves, but after throwing his green jacket into the fireplace, his gloves disappear entirely. (04:25:03 - 04:29:59)
Other mistake: When Alfred serves Bruce coffee at the end, there's no steam coming from the coffee pot or Bruce's mug when Alfred pours the coffee into mug.
Continuity mistake: Riddler's gloves disappear briefly after Batman confronts him at his party.
Continuity mistake: Harley's shoes are poorly drawn when she dances in Dr. Leland's office.
Continuity mistake: Both of Harley's shoes are red as Batman holds her after rescuing her from falling.
Continuity mistake: Batgirl and Catwoman briefly gain pupils in one shot of them during the Stacked Deck fight, despite not having any throughout the episode. (04:00:39 - 04:41:24)
Continuity mistake: Batgirl's cape changes length throughout the episode. It goes from reaching her ankles to her hips.
Continuity mistake: When she was pulling Daggett up, Batgirl briefly gains pupils when she says "Catwoman, wait."
Continuity mistake: The soles of Batgirl's boots change from light to dark blue throughout the episode.
Continuity mistake: Batgirl's boots gain and lose heels throughout the climax of the episode.
Answer: She escaped off-screen and created a copy of herself to fool everyone.