Continuity mistake: During the boat trip at the beginning, wind knocks the hat off the judge's head in a close-up. The action happens again in the next shot, but it is starting with the hat reclined on the actor's face, flying across with a lower trajectory. (00:02:10)
Continuity mistake: Mischa Auer is seasick, and feels even worse with the ferryman's snack right in his face. The man is holding the sandwich in one hand, and the other hand in frame is relaxed in his lap; however he has it on the rudder bar in the next shot (as he should with the sea in that state). (00:02:45)
Continuity mistake: The ferryman hands the letter to the butler; a left hand pops in frame to fetch it, but in the next shot the butler's outstretched arm is the right one. (00:04:00)
Continuity mistake: General Mandrake introduces himself and leans back against the chair, leaning back again in the next shot. (00:07:00)
Continuity mistake: Ethel Rogers drops the tray in the kitchen; the oven is open and many fumes come out of it. She kneels with her husband to salvage the food, and the vapors are gone. (00:09:20)
Continuity mistake: After the toast to Mr. Owen, the General retorts that hopefully all the possible toasts are done. Vera Claythorne puts down her glass, but in the next shot the whole arm is gone from above the table, she has her hands in her lap. (00:10:35)
Continuity mistake: When a drunk Prince Nikita Starloff is quick to make yet another toast in honor of the Indians and their statuettes ("I drink to the Indians!"), Lombard who had his hand down on the table, has it raised in front of his chest. (00:10:55)
Continuity mistake: As Ms. Claythorn recites the first verse of the nursery rhyme, Lombard picks up food from the platter. He gets two pieces, then puts the utensils back; notice in the following shot how his arm is suddenly in a different and rather awkward position, the waiter being at closer distance. (00:11:15)
Continuity mistake: While Prince Nikita Starloff plays at the piano in a creepy deep voice the Indians song, a poker game is going on. Rogers serves the drinks; at the cut when he walks away, the General's pipe switched side of the mouth. (00:12:15)
Continuity mistake: Blore gets up from his chair during the Ten Little Indians song. Through the doorway you can see the Doctor and the Judge playing pool; cuts to a closer view and Dr. Edward G. Armstrong is in an entirely different posture and position. (00:12:35)
Continuity mistake: At the end of the macabre performance at the piano by Mischa Auer, he grabs his drink and raises the glass - which is lowered at the instantaneous cut to a new angle. (00:13:30)
Continuity mistake: When Mrs. Rogers yells at her husband, behind her in close-up you can see on the portion of floor in frame the silverware she was carrying and that is by her; she moved forward quite a bit. (00:16:20)
Continuity mistake: After his confession, the prince plays the piano no-stop when he's not in frame, but the glass awaits him closer on the sheets than it originally was when he picks it up to toast yet again. (00:19:30)
Continuity mistake: The prince tells the sad story of his driving license revoked - with two people dying as collateral damage. Judge Francis J. Quincannon stands and then leans over the back of the chair; his arms switch position, crossing with the right in front, then the left in front. (00:19:50)
Continuity mistake: When the doctor announces that "Mrs. Rogers died in her sleep", the Judge 's hand with the pipe goes from in front of the chest to down his side. (00:25:00)
Continuity mistake: In the scene with the various characters (Blore, the doctor, the judge) spying on each other, the keyholes the camera looks through are always perfectly lit, with none of the shadows the characters cast on the lock in the other views. (00:27:25)
Continuity mistake: Blore asks Lombard from the other side of the door "You mean you haven't any weapon?", hands off the handle. Hand on the handle in the shot that follows. (00:27:30)
Continuity mistake: Miss Emily Brent points her binoculars at the beach in the same shot when the men decide to start searching the island. She witnesses a brief exchange between Vera and the General, then follows Vera's movements who are in strict continuity. Merely a minute has passed, and the guys already are on the beach (which already can be quite a feat) discussing how their search was fruitless. They haven't searched a thing in so little time. (00:30:25)
Continuity mistake: Vera reaches on the beach Gen. Sir John Mandrake. When she exclaims "Sir John!" after he asked her (or rather, his dead wife) why does she love 'him', the sky is overcast and the shadows change radically in the next shot. (00:30:50)
Continuity mistake: Vera approaches the General on the beach. He calls her "Juliet", mistaking her for his dead wife; during the close-up on June Duprez, the lighting is different and the foulard is windblown harder. (00:31:00)