Revealing mistake: Several pieces of furniture, including a large sofa, fall over before the suitcase bomb actually explodes.
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)
Revealing mistake: After Holmes reveals that Mr. Potts is Ransom, the detective and the murderer have a conversation. After Holmes says 'No, not necessarily', the shot changes. In the next shot, you can see that the man standing in front of Basil Rathbone is not Gerald Hamer. This man has much less hair than Hamer and has a broader forehead. (01:10:39)