Factual error: During the first scenes of the film the Greek flag used is the current one, and not the one used at that time. The flag that should have been used is a white cross on blue.
Continuity mistake: When Cage is talking to Cruz for the second time, Cruz's hair changes shape. There's also dirt on her shoulder which disappears in the next shot.
Factual error: The "tank" seen throughout the film is actually a specialist "tank hunter" and would only have operated as part of a specific unit, it would never have been assigned on its own to a Greek island where there were no tanks to hunt.
Factual error: During the discussions among the Italian officers regarding the surrender of their weapons to the Germans, one of them mentions "Mussolini surrendered to the Americans, not to the Germans". Mussolini had been remove from government for over a month when the Italian Government agreed to its armistice with the allies.
Continuity mistake: When the German planes are bombing the town and harbour, it is very apparent that the planes are computer generated. The detail of the planes is excellent, but the movement through the air is not consistent with a real plane.
Factual error: In the scene where the radio at the bar in town announces that Rome has fallen to the Allies, a group of Italian soldiers in a truck arrives celebrating that the "war is over", because "Mussolini has fallen". First mistake, Mussolini fell several months before the Allies got to Rome. Second, the fall of Mussolini did not remove Italy or its Army from the war. The armistice between Italy and the Allies came almost fifty days after the fall of Mussolini, and did not end the war, because a part of the Italian army remained with the new Republic created by Mussolini, and the other part went on to fight with the Allies.