Deliberate mistake: In the scene where the ministers are all crammed into the train carriage if you look over Jim's shoulder there is a sign ("Notice" "In case of Fire" etc), while the headers are in English the actually paragraphs are written in gibberish.
Deliberate mistake: When Magnum first meets Geoffrey's wife, Penelope, the shot facing Magnum as he asks her if something is wrong, is the start of a series of flipped shots facing each of them during this scene. (00:11:30)