There is a montage of battle scenes which show tanks being used in battle. Neither Russian nor Austria used tanks in the Great War.
Colonel Kranau escapes and steals a plane to flee. This would have been close to impossible for anyone to do by themselves with aircraft of this era. Mechanics and other support crew were needed to spin the propeller to start the plane as the planes lacked starter motors. Other support crew were needed to remove the chocks from the wheels to allow the plane to taxi once it had started.
In the execution scene, there is a shot showing the drumhead with shadows of two rifles on it. The angle at which the drum is held by the drummer would not allow these shadows to appear, and even if it did, the rifles are facing in the wrong direction.