The Letter - S5-E7
Factual error: Sgt. Saunders is looking at a color photo of his kid brother in a letter from home. Aside from being prohibitively expensive for the average family to afford, color photos were not common. Also, the wartime rationing of photo chemicals for color film used by civilians would not be available.
Factual error: As Caje provides cover fire for Sgt. Saunders, Caje's M-1 rifle fires more than the eight shots it holds.
Factual error: As Stevens charges the German machine gun nest, he fires more bullets than his M-1 rifle could hold (the rifle could hold only eight rounds per clip).
The Losers - S5-E2
Factual error: As Sgt. Saunders and his squad dodge artillery fire in the ruined city, modern high-tension electrical towers are shown. Also, no electrical towers whatsoever would have survived a prolonged artillery bombardment without being damaged or destroyed.
Factual error: The long shots show the supporting tank reversing, but the close up shot of the tank's drive sprocket shows the drive sprocket moving forward, thus the tank should be moving forward, not reversing.
The Short Day of Private Putnam - S2-E28
Factual error: The German snipers are wearing American-issue camo jackets.
Factual error: McCall shoots a German ten times with his M1. But the M1 could hold only eight bullets.
Mountain Man - S3-E1
Factual error: Combat is set in Northern France, where there are no snow-capped mountains. Yet Saunders' troops are crossing such terrain here. It's also apparent that, despite dialogue referring to sub-zero temperatures, it isn't really very cold. The actors are sweating in their snow gear, there's no frost on them, and no one's breath is forming any clouds in the air.
Factual error: The planes Hanley identifies as Messerschmitts aren't. They're stock footage of U.S. P51 Mustangs.
Factual error: The German radio-wave detection vehicle is a very poorly disguised American ambulance.