Other mistake: Based on the location of the barber's chair with the picture window in Todd's barber shop and the layout of the exterior of the building, there is no possible way that the chute behind the chair would be able to dump the bodies directly into the basement without going through the center of Ms. Lovett's shop.
Continuity mistake: When Giselle opens the window in Robert's apartment, in the exterior shot, to sing for furry cleaning help, there is a set of three windows to her right, with a balcony. Odd thing is, in the interior shots the window she sang from is to the left of the couch, but to the right of the couch there are three French doors, not windows, that open to the balcony. (00:25:20)Super Grover
Continuity mistake: Near the end, when Lucy tries to get into the building, she is blocked by police officers holding clubs straight ahead in front of them. The scene cuts to a roof shot, then back again, and Lucy tries again, but the clubs are missing, the cops just have their hands out in front of them.