Deliberate mistake: When Fagin shakes Oliver's hand (when he first meets him) there is a blonde haired boy standing right behind Oliver, but in the shots from behind him, the boy is gone. This may be because the camera is just behind where the boy was and he had to move so they could get the shots from this angle.
Deliberate mistake: As Rosemary is prepared to be raped by the devil she is lying on white sheets. In the next shot as she is being raped she's on black satin sheets. (00:47:30)