Continuity mistake: When the lodger is looking down the stairs at Daisy (who has just been handcuffed as a joke), his body faces the railing in one shot, the wall in the next, then the railing again.
Revealing mistake: When we see for the first time cops fish out of the river one of Bluebeard's victims, the "lifeless body" helps herself up on the boat, practically climbing on her own. (00:02:15)