In the several fighting scenes, close-ups of the American soldier firing a German MP40 on fully automatic, but the gun is not expelling any spent rounds and the bolt is stationary. The same is seen while firing his semi-automatic pistol.
The British soldier near the end of the movie is seen firing a semi automatic pistol. The camera angle is looking down the barrel, and a blockage can be seen that would cause a real gun to misfire and jam, if not explode..
An aerial view of three Germans shooting at the allies shows all 3 with muzzle flashed of fully automatic fire, but 2 of them are hold bolt action rifles and are not reloading after each shot.
When the American is seriously wounded, he hands his dog tags to the British soldier to give to his son back home, and then promptly leaves him in the battlefield. Somehow this American soldier that no longer had any ID on him miraculously can be found years later in an extremely British graveyard with a marked headstone.
Fresh magazines can be seen loaded into weapons during a battle but the view is close enough to reveal that fresh magazine is empty.