Factual error: The German tanks are American M47s, post WW2. They had the same hulls as the M46s (also post-WW2), but a better slope and greater effective armor on the turrets.
Factual error: At the end of the movie, during the final battle scene, Lieutenant Colonel Robert Frederick checks the time on his watch (a Longines Admiral). Yet, that watch was made and released in the 1960s, not during the 1940s where the movie was set.
Factual error: In the scene of the battle on top of the mountain it looks like the Germans have American M116 (75mm) howitzers as part of their weaponry, only visible for a short while.