Visible crew/equipment: When Lionel returns to the jazz bar and discovers Billy Rose has been killed (framed as a suicide), you can see two people standing in the shadows to the left of Lionel as he enters the main room where the stage is located. A man is hunched over, whilst a woman is standing still wearing what looks like a dust mask. (01:32:27)
Continuity mistake: Young Shaft is meeting his friend at the bar: he has just his solitary drink before him when Karim arrives, but the drinks are now 2 with Sasha's arrival - only for a single shot, though, as just a single glass is afterwards. (00:11:40)
Continuity mistake: En route from the front door of Wayne's mansion to the table in the Batcave, the pile of pizza boxes in Alfred and then in Mike's hands continues to change in size and number: at first the pizza girl delivers 11 boxes, Mike slams on the table just 8, but he brought down the stairs twice that amount (without counting through freeze-frame the precise numbers, it's simply obvious at first glance that the pile is bigger in some shots and the pizzas themselves are pictured of inconsistent size).
Continuity mistake: When Joker confesses that he was the one who killed the three guys in the subway at the Murray Franklin Show and also says "It's not a joke", he keeps his gaze turned towards Murray in one shot and towards the audience in the next.
Continuity mistake: When Jimmy is sitting with Frank at the restaurant complaining about the fact that Tony Pro is late, we see Frank holding a Coca-Cola bottle with the right hand, but in the next shot the hand disappears from the table and stays down resting on the chair.
Visible crew/equipment: As the camera moves forward in the opening shot, a clear reflection of a film light can be seen on the side of the fire engine.
Continuity mistake: Leah asks Moose if he brought the cutters, so he looks in his bag then hands Leah scissors. In the shots facing Leah she holds up the scissors by its handles, but in the shots facing Moose she holds up the scissors by its pointy end. (00:10:20)
Other mistake: Elsa Brecht is holding an official piece of mail sent from the Coconut Grove Hotel in Miami but it's postmarked Orlando, Florida. There's no legitimate reason the mail would be postmarked Orlando when Orlando is 235 miles from Miami. (01:24:16)