As Stanford is driving his race car, the reverse shot of the steering wheel clearly shows a large ring on his right hand. In the cutaways showing Stanford's face, no ring is on his hand.
When Robert is arguing with Honor while David, first slumped in a chair in the next room, is now waking up from his drunken state, Honor's hair is tied up neatly behind her head. As Robert approaches her menacingly (before striking her), the camera suddenly turns to her and her hair is now hanging free, she has a hurt look on her face, and is touching her cheek as one would do after being stung by a slap. Then the camera then turns to him, shows him swing at her, after which she is shown falling face-first onto the bed.
When David first gets into the sports car with Brian and they drive off, David is a good half a head taller than Brian with David's eyes approximately at the height of the top of the windshield. In subsequent shots when shown from the front, David and Brian are the same height in the car, David's eyes now well below the top of the windshield.
David Graham (Michael Redgrave) is shown as arriving in the UK on a British European Airways plane. However, he is flying in from Canada, which was served by BOAC (British Overseas Airways Corporation).
When Stanford is driving Graham, there is an interior shot of both from behind and the RPM gauge reads zero.
Early in the film, what is supposed to be a showroom for "Stanford" Motor cars is a Rootes showroom. The names Hillman and Commer, both Rootes products are clearly stenciled on the window. Also, the Stanford logo, visible on the office wall, is simply the Mercedes Benz three-pointed star with a couple of extra circles. Later, the "Stanford" car that Robert Stanford drives at the proving ground is a Mercedes-Benz 300 SL gull-wing coupe, one of the most easily recognizable sports cars of the 1950's.
When David Graham is arguing with the prison chaplain (circa 50 mins), the clock on the wall shows 16.02. Graham turns and walks three steps to the clock and turns again to speak, the clock clearly shows the time to be 16.07.
The camera crew is reflected in the door of Clayton's car as it pulls up at the prison with Graham.