Factual error: The "Blue Baron" tells the dancer that the Kaiser gave him a certain medal. In fact, the medal he points to (and the girl fondles) is a WW2 repeat badge to the Iron Cross first class, instituted in 1939 to denote presentations of the Iron Cross first class to personnel who had already received it in WW1. He may have received the original Iron Cross from the Kaiser, but by the time he had a chance to receive that repeat badge, the Kaiser was long through handing out medals.
Factual error: In the tunnel Hogan loads a magazine into a US issue .45 pistol and points it at Myra, but he never chambered a round and didn't cock the hammer on the pistol. The .45 pistol in WW2 was single action. For a single action pistol to fire, a round needs to be chambered and the hammer has to be cocked manually before the trigger is pulled and the pistol to fire.
Factual error: When the farmer sticks his pitchfork into the haystack, a scream is heard, but then everybody emerges unscathed. Wounds from pitchforks aren't like sitting on a brass tack - even a quick jab usually earns you a trip to the surgeon (I've seen such wounds), a vigorous stab like the one in the scene would go through limbs and could easily kill a man. There's no way anybody would walk away from such a hit.
Factual error: The medal Newkirk steals from the German officer in the pub is a Knight's Cross of the Iron Cross with Oak Leaves and Swords. There were a total of 148 presentations, most of them 1943-45. By 1942 (where the series is apparently set), less than 25 had been presented. That Newkirk should actually stumble across a wearer by pure chance is highly unlikely, that the wearer should actually "never miss it" as Newkirk states, is plainly impossible. Being the fourth highest ranking military decoration of the Wehrmacht, it would have been missed almost immediately - if not by the wearer himself, then by his fellow officers.