Continuity mistake: In the scene where Willem Dafoe is conversing with another male British agent as the German paratroopers invade, a British female worker passes him as he is about to go down the flight of stairs. As he reaches the ground floor, she passes by him again as she goes up the same stairs he just came down - seemingly far too quick to be possible.
Continuity mistake: In the scene where Almacy is trying to dig out the workers from the car in the sand dune, the camera switches back and forth between Almacy and Katherine as they talk. Each time the camera shows Almacy, the long white scarf around his neck is wrapped or dangling in a different way, and missing entirely at the end, as if they were tired of messing with it.
Continuity mistake: In the airplane crash scene, the stunt plane's fuselage appears to be seriously damaged. But when Fiennes runs up to the airplane to pull out the Cliftons, the fuselage looks relatively undamaged.
Plot hole: It's unusual for Juliette Binoche's nurse to have a beautiful blue dress on when she retires with "her" patient to the abandoned monastery. Maybe it was an artistic homage by the film's director to her marvelous leading role in the movie, "Blue." However, given the unstable situation in post-war Italy, shouldn't she still be wearing her British khaki Army uniform?
Factual error: In the interrogation scene with Carravaggio, the German officer is addressed by the private Wehrmacht soldier as "Herr major". The officer is SS. By his shoulder patches he indeed has the equivalent rank of a major, but the correct SS rank is "Sturmbannführer". SS officers were never addressed as "Herr", but simply with the rank.
Factual error: Radial tires - bulging - and jeep-like tread in 1914 on the pickup aren't right. Most of 1914 tires were bias ply and very narrow, like 6 inches wide.