Revealing mistake: The first morning the new Mrs De Winter is at Manderley, she goes to have breakfast, but when she attempts to pour milk into her coffee, there's no milk in the jug; she's just pretending to pour it.
Revealing mistake: When the defective shell is about to fall, the ground has no sand mounts. Couple shots later, now on the floor, the shell turns around following Chaplin. Watch and you'll see that a sand mount has magically appeared close to the shell to hide the white mechanism that makes the bullet turn.