The Letter - S5-E7
Revealing mistake: The same strawberry-blonde haired stuntman (Paul Busch) is used three times: first as an American G.I. being shot, then as a German soldier being shot, and again as another American G.I. being shot - all in the same battle scene.
The Gantlet - S5-E20
Revealing mistake: During the close combat scene between Sgt. Saunders and the German soldier, it is obviously Vic Morrow's stunt double doing the heavy action and fighting.
Revealing mistake: A German soldier steps out of a doorway ready to throw a grenade, but he gets shot, dropping the grenade a couple of feet in front of him. However, the explosion from his dropped grenade occurs from within the doorway itself.
Revealing mistake: When Sgt. Saunders throws a grenade at the German soldiers shooting at him from behind a crate, the grenade lands in front of the crate, but the explosion is actually behind the crate, where the Germans are.
Revealing mistake: Blank .30 caliber machine gun bullets are obvious as the soldier with Little John sets up and loads the weapon.
Revealing mistake: The German MP38/40 submachineguns have blank firing adapters on their barrels.
Revealing mistake: Blanks loaded in the German MG42 are obvious as the American tank assaults its position.