Continuity mistake: Vera fires the gun several times, and later tells Justice Wargrave that the gun is empty, meaning that all the cartridges in it would be spent. When the judge loads his one bullet into the chamber, he does so in a gun where all five cartridge svisible are unspent.
Continuity mistake: Dr. Armstrong at the beginning of the episode squeaks that they should light a fire to signal the danger. Close-up on the judge, holding his cane with the sole right hand, thumb up along it. Next shot and he has both hands on the cane, thumb tucked in. (00:03:50)
Continuity mistake: In the first flashback of the episode, Vera prepares to be the batter.Behind her, a large lady with a green sweater walks twice, starting further behind the original position at the cut. She was also passing by earlier when the kid and her beau were playing on their own. (00:03:25)
Continuity mistake: Searching for the gun and the key, Armstrong frantically throws on the floor books from two shelves. The second time the shelf is in frame - when Judge Wargrave looks tired and shakes his head - the lower shelf looks fuller than in the first shot. (00:52:50)
Continuity mistake: When the men carry inside the corpse of the General, Emily Brent has her hands in front of her tummy or at her chest depending on the camera angle, and the Judge is fiddling with the pocket watch chain in close-ups, but not in the wider angles. (00:22:50)