Deliberate mistake: The German army is using American Sherman tanks, presumably easier to get for filming.
Deliberate mistake: Smith and the team come down the mountain and into the village at dusk, yet it is light out during the entire movie.
Deliberate mistake: In the scene near the end of the movie when Trigger is in the bilge trying to stop the air leak, the concussion of an artillery shell fired from the destroyer shakes some pipes loose. The mistake is that one of the flanges visible on a section of pipe has no bolt holes, making it impossible to join that pipe to anything.
Deliberate mistake: The German tanks in this movie are not really Tiger tanks. They are Russian T-34's made to look like Tigers. The T-34's are done up very realistically, including Zimmerit (the wavy pattern on the hull of the tiger), which was an anti-magnetic paste put on the tank.
Deliberate mistake: The Glock pistol the dying Russian assassin attempts to fire clicks, symbolizing it's out of ammo, or had a malfunction such as failure to ignite primer which is extraordinarily unlikely. His action symbolized a dry weapon. When a modern handgun in particular a Glock runs dry, the slide stop lever engages the slide and leaves the slide open until a new magazine is inserted and the slide is racked or the slide stop is pushed down. On a dry Glock the trigger can't be pressed until the slide is cocked. (00:16:45 - 00:17:30)