Anachronisms: Elsa's rural farmhouse in the mountains has electric lighting in the 1910s.
Anachronisms: As the WWI German soldiers are celebrating a French fort's capture, the map on the wall of the officers club is clearly an inter-war (1919-1938) map of Germany.
Continuity: When Lt. Maréchal is climbing down the rope from the watchtower the wooden window shutters can be seen closing above him even though he closed them himself minutes prior.