Revealing mistake: A boulder tumbles towards James Mason and his party though a cave. With all the smashing against the walls and floor of the cave, the boulder stays entirely intact. However, just before the boulder hits a wall with two tunnels while flying through the air, the boulder now shows two majors fractures that were unseen earlier. The fractures were added to the boulder to give it a more dramatic impact by it breaking up with one piece nearly striking James Mason.
Continuity mistake: James Mason meets the villain (Thayer David) who holds a gun on Mason and the rest. Mason outwits him by throwing salt into his face to blind him. When the salt hits his face, he closes his eyes (too early) before impact. The salt impact hits the right side of his face. An angle change occurs and we see a close-up of him (or a stunt double - his hair is different) and the salt hits the actor squarely in his face with his eyes open to the last microsecond. The scene changes back to show Mason and the villain with the salt on the right-side of the villain's face again with him in agony.