Continuity mistake: When the 'sole' survivor walks into the supposedly empty house and spots the noose, it is placed quite high. When they walk back into the room with Owen, the noose is dangling low enough to nearly brush against his head. (01:31:35 - 01:32:25)
Other mistake: In the flashback of the denouement, Dr. Armstrong is shown dead face down on the beach, with the feet pointed ashore and the head to the sea. Mr. Owen takes also a sip from that Armstrong's flask and tosses it in the sand without capping it. However, Vera and Lombard found a corpse face inland and feet to the sea, and a flask with its lid in place. (01:28:50 - 01:34:40)
Revealing mistake: Mr. Owen's dramatic appearance begins with a precise pool shot. But Owen is standing behind the table in a position incompatible with the angle the ball was shot from - someone else out of frame must have performed that shot. (01:31:50)
Continuity mistake: During the confrontation between Vera and Lombard at the beach, their hair is windblown with intensity that changes at every cut. (01:29:05)
Continuity mistake: On the beach, Vera and Lombard are quite literally pointing fingers at each other...except they are not; new shot, different pose. (01:29:10)
Continuity mistake: Inside Vera's room, she retorts "What about me?" when Lombard tells her his theory about who Mr. Owen is. The shots have different lighting, with either an overwhelming shadow from Lombard on her, or barely any shadow at all. (01:20:05)
Continuity mistake: Lombard is protecting Vera's door, preventing the doctor from entering. Armstrong says "Oh but you will, you will." You can notice the double shadow projected by him, and Lombard's more marked but single one, mostly into the frame and not the actual door. Nobody moves candles of any kind in the next seconds, but when Armstrong after his explanation gets again in Lombard's face, Lombard is projecting a big shadow on the door and Armstrong none. (01:16:40)
Continuity mistake: When the doctor proclaims the Judge dead, Lombard and Bloor's position on the door changes - they are close together, then more distant, then shoulder to shoulder again. (01:14:30)
Continuity mistake: The doctor is watching the others when Lombard says he heard a shot. The close-up on Walter Huston shows him with a totally different facial expression compared to the previous and following shots, and the shadow he casts on the wall is also different (it's also incongruous, since in theory the only light comes from either his candles or those from others in front of him, but he projects a shadow to his side/front). (01:13:35)
Character mistake: Blore accuses Lombard saying "What about those 21 poor natives in South Africa?" The record played during the first evening mentioned indeed 21 men, but that were natives of a tribe in East Africa. (00:14:20 - 01:10:10)
Continuity mistake: When the Judge asks Blore to confess saying "We're listening, Mr. Blore", Blore is clutching the napkin. As he begins to speak in a new shot, the cloth is gone from his hand. (01:09:50)
Revealing mistake: Dr. Armstrong uses his lighter, which, true to its name, lights the room. The whole room, with a disproportionate intensity. Even if you consider it as an acceptable exaggeration for practical purposes, especially in such old motion pictures, the set lights are turned on with half a second of delay, making the trick painfully obvious. (01:07:40)
Continuity mistake: When the Doctor and the Judge realise that they are on their own at the billiard table, the Judge holds his cue stick towards the left, right, left. (01:05:25)
Continuity mistake: When Lombard tells Vera "Don't you think it's strange that there's never a third person present when anything unpleasant occurs?" his cigarette is in the left hand, and switches instantly to the right in the next shot. (01:03:35)
Revealing mistake: The 'bee' on the window - immobile in the first shot - is just a dummy with static wings. (01:00:45)
Continuity mistake: When Emily Brent is found in her room, the light of the area changes between shots - just look at the direction the legs of the first responder cast a shadow at. Also, the position of his feet is different; he already almost reached the door in the previous shot, and is 2 boards behind in the new one. (01:00:10)
Continuity mistake: In the scene preceding Emily Brent's death, Judge Francis J. Quincannon moves his glasses around, creating a couple of obvious discontinuities, first when his hands from distanced become joined at the very beginning, and then at the bottom of the stairs when he waves Blore to stay put. (00:58:50)
Audio problem: Blore, just wearing his pants and tanktop, razor in hand, opens the door between his room and Lombard's. Louis Hayward and Roland Young have an exchange ("Whatchya doing here?" "You called me, didn't you?") with barely half of the words mouthed, the audio does not match. (00:58:20)
Continuity mistake: Vera is in the kitchen serving boiled eggs to Emily Brent. Vera calls Emily on saying something suspiciously akin to Mr. Owen's ideals; Emily walks away and Vera turns around. The continuity is broken by the position of Vera's left hand, horizontal in the first shot, vertical in the next. (00:55:50)
Continuity mistake: In the kitchen scene where Lombard reminds Vera the ominous bumblebee line, Miss Brent's position in front of the cupboard changes continuously. (00:55:10)
