When the teenager is writing in white chalk on the wall, the position of the words changes from one cut to the next.
The cardinal somehow remains clean shaven throughout, even when held in solitary confinement for weeks. He has access to cutlery (a knife and fork), but it is only brought into his cell to eat his food with, and is removed with the plates and tray etc afterwards whilst the guard watches him eat.
Late in the film Jack Hawkins snatches a newspaper from a woman at an outdoor cafe. Although the interior text about the cardinal's confession is in English, the outside can be seen to be 'Het Laatste Nieuws', a real Dutch-language Belgian newspaper. (Some of the film's exteriors were shot in Flanders.)