Continuity mistake: Shadow of the dolly against the smoke of battle during the invasion of Omaha beach. The direction of the shadow and the geography of the beach indicate that this scene, while set at dawn, was filmed in the afternoon.
Continuity mistake: The German General Pemsel says, "Wir haben starke RADAR-storungen," which means "we have strong radar interference." In 1944, the word "radar" was not used in Germany, and quite likely not even known. The Germans used a comparable system, called "FunkmeBgerate," which basically means "radio measuring equipment."
Continuity mistake: Sgt. Fuller's stripes disappear (actually one stripe is hanging from his uniform) as he is running with the detonation wire. They reappear in perfect place when he is about to detonate the first charge.
Continuity mistake: When Wodarczyk and Priller bombarde the Gold-Juno Beaches, the barren beach - devoid of men, vehicles, etc., is visible in the overhead shot, just past the small strip of beach used for the shoot.
Continuity mistake: In the scenes in the square at Ste Marie Eglise you can quite clearly see the war memorial (vaguely disguised by a tarpaulin or something).
Continuity mistake: Near the start, Oberst Helmuth Meyer enters, wearing a long leather coat, which is dry. A few seconds later he turns away in another shot and the back of his coat is covered with rain drops. Shortly after that, he's shown again facing the camera and his coat is lightly sprinkled with rain drops, which weren't there in the earlier front view. (00:06:20)
Continuity mistake: On Omaha Beach, the engineers are able to use Bangalore Torpedoes to create large openings under a massive concrete barrier at the end of a sandy ravine. They then pack the holes with high explosives and after the dust clears, the barrier is about half as high as before, with two large sections remaining in the breach. In an immediately following scene, as troops advance through the breach, it is shown from the opposite side as a wide, flat opening, nothing like the view from the beach side.