During the coronation scene, the bishop pours oil out from a container onto a spoon even though there is already oil on the spoon. Also, when he makes the pouring motion, nothing comes out of the container.
When the Duke of Windsor has a meeting with the Archbishop of Canterbury, the cost of arms of New Zealand is visible in the stained glass window behind the archbishop. This coat of arms was adopted in 1956 whereas this episode is set in 1953.