When Saunders is seen looking through the binoculars, the lenses keep changing from clean to dirty. Also, studio lights are seen reflecting in the lenses.
When Saunders chases a German soldier into a cave and shoots him, the German crashes into the cave wall and it moves.
When Saunders creeps up on a German guard with his bayonet outside the cave @50 min mark,the Germans gun fires but you hear a Tommy gun sound effect.
When Kirby enters the cave @52min mark he fires on the Germans. Again you hear a Tommy gun sound effect instead of the usual BAR.