Flamethrowers seen in all night scene was an M1, with long double tube. In the main attack, the two men dying carry both M2 flamethrowers, with a pistol grip near the muzzle. But when Colby grab one of those back, and use it on the bunker, it's a M1 again.
The final attack is to take place at 6:00 AM. Judging from the shadows, the attack scenes were filmed between 11:00 AM to 1:00 PM.
When Reese, Henshaw and Kolinsky are low crawling through the mine field they are trying to find mines with their hands at night. This would be suicide. The actual military way to find land mines is by using a bayonet and probing with the tip at an angle into the dirt.
McQueen's weapon of choice is his M3 'Grease gun' submachine gun. Yet he carries ammunition pouches for rifle ammunition (5-8 round clips) not 32 round M3 submachine gun clips.
On the line Pike asks Reese what do they have down there? Reese responds "9MM light". The German machine gun would have been either an MG34 or an MG42, both 7.92 X 57MM standard rifle size rounds in German Army.
A 9MM is a small pistol round used in machine pistole (burp guns), not in machine guns as "Light" may imply.
Homer would have been sent to the Polish 2nd Corps to become a soldier. Displaced Poles were picked up and added to the ranks of these units as they marched through Holland and Belgium. At Normandy there were 195,000 Polish Army troops at the war's end there were 237,000 troops under arms. It is said that the Poles recruited from the front. Poles conscripted into the German army was a primary source, but any displaced person would be absorbed.
During the final charge on the pillbox, no German machine gun shown firing from the pillbox. The gun would have to be placed so the barrel would be outside the opening for maximum effect.
When laying out the ammo boxes connected to wires: A) It is night but there are obvious shadows B) The wire reels movement does not correspond to man movement. While moving through rough country, the wire spools unroll rather smoothly. C) When the lines are laid, the hands shaking the wires move only slightly, but the ammo boxes shake wildly.
During the final battle, a German gives the order "Achtung, Fire". In addition to mixing German with English, the use of "fire" as in "fire when ready" in German "Feuern Sie, wenn vorbereitet" is meaningless. "Fire" in this context is an American term.
And again when Reese, Henshaw and Kolinsky are low crawling through the mine field , Henshaw is wearing a pair of glasses which is a terrible mistake in real military operation at night because of light reflection.
Every time McQueen's right wrist is seen, in the bar and in the field, it's clear that he's wearing a modern watch with a stainless steel bracelet, like a Rolex or Heuer. It would also be inappropriate in combat as it would reflect any light, drawing unwanted attention to the soldier, not to mention several rounds.