Continuity mistake: Trying to protect Salvo, Riley punches two thugs. The second one is a red bearded man. The big boss urges then the other baddies to attack, and redbeard is way behind him, hasn't leaped into action yet. (00:11:35)
Continuity mistake: The 10/6's on the Mad Hatter's mind control cards come and go throughout the episode.
Continuity mistake: The 10/6th on the Mad Hatter's mind control cards come and go throughout the episode. An example is when he first is shown holding them they're blank. Then when he decides to use them on his date with Alice they've suddenly got the 10/6th.
Continuity mistake: When Jervis Tetch is shown he's around 5'5 maybe with blue eyes and sandy white looking hair. Yet the day after his night out with Alice he's suddenly around Bruce Wayne's size with blond hair and his eyes are no longer blue.
Continuity mistake: When the Matron fails to draw the taxi's attention, a couple passes by her (she wears a blue raincoat and a purple beret) but they were nowhere in sight in the wide angle. (00:02:45)
Continuity mistake: The policeman that writes down the woman's leprechaun sighting is using a brown and yellow notepad in the first shot, which turns into a white paper sheet in the next. (00:03:05)
Continuity mistake: Alfred is skilfully dancing while sitting and sipping tea. The radio rests next to a circular monitor on the computer. Then on a featureless spot, then directly on the monitor itself. (00:04:05)
Continuity mistake: The content of the table of the Sewer King constantly change when he has his messy dinner. At the end he flips the table and throws everything on the floor, and the floor is clean a second after, even. (00:12:35)
Continuity mistake: Gathering evidence inside the Sewer King's lair, Batman's camera changes size (it gets bigger) and shape (the button is on the left but it started on the right). (00:15:55)
Continuity mistake: Batman blasts the last door between himself and the villain. The floor is in frame for a lengthy time and there's no trace of debris, but in the next shot Batman passes the remains of the door. (00:20:35)
Continuity mistake: Both Selina's, once she's been mutated, and Tygrus' noses change color. Hers goes black briefly when she finds Batman in the forest and Tygrus' turns grey briefly as Dr Dorian scolds him.
Continuity mistake: Scarecrow's shoes are light brown in most of the episode. Yet once he's back in his cell they're suddenly dark grey.
Continuity mistake: When Batman stops the countdown it reads as 1:45. When Scarecrow starts it back up it's suddenly 0:14.
Continuity mistake: Scarecrow's pants turn red when he's on the catwalk turning on the pump machine.
Continuity mistake: At the end of the episode, Selina is wearing a purple vest and grey sweater, but they change to red and purple when she is holding Isis and watching Batman, and they change back to purple and grey as she cuddles Isis.
Continuity mistake: For one frame during the final battle with the werewolf, the logo on Batman's chest is black and white instead of black and yellow. (00:17:55)
Christmas With the Joker - S1-E38
Continuity mistake: During the wacky scene of the Joker's escape, the balls on the Christmas tree vanish /change position and size between shots. (00:01:35)
Christmas With the Joker - S1-E38
Continuity mistake: In the scene with the old lady and the lad who brings her the package she dropped, the red stripe on the golden package changed position between shots. (00:03:50)
Christmas With the Joker - S1-E38
Continuity mistake: Joker puts in the mouth of "the Lawful family" members candy canes that they can't spit away. He puts back in Summer Gleeson's mouth the cane with the hook pointing up, but it points down when he's done with Bullock. (00:07:40)
Christmas With the Joker - S1-E38
Continuity mistake: The Joker's goons blew up the bridge, and Joker turns to the three hostages. Bullock's candy cane is facing Summer's, but the Joker put it in his mouth facing the other direction. (00:07:50 - 00:09:40)
Answer: She escaped off-screen and created a copy of herself to fool everyone.