Other mistake: When Hawkeye drives the damaged tank out of the camp, the front MG is missing. There's not a mark on the armor surrounding the MG port that might suggest it was destroyed in battle. Why would a tank in combat just be missing one of its MGs?
Continuity mistake: As Hawkeye climbs under the table to hide there are three small stacks of white bandage boxes on the table. When the shelling starts, all the boxes in two of the stacks fall off the table, leaving one stack. When the shot changes, there are suddenly two stacks of boxes on the table.
Revealing mistake: In the shot where the horse kicks in the door, there's actually two shots - a kick, a quick cut, another kick. If you look closely, you can see how the hoof of one of the horse-leg props breaks off during the first kick. The second kick is performed by one leg only. If you look really closely - and probably use the slow-motion function - you can even make out the hand of the one wielding the leg through the hole made in the first kick.
Factual error: In this episode, Henry is seen handing Radar the keys to his jeep. While this probably benefited the understanding of the audience, it is historically incorrect. Jeeps assigned to a combat zone were outfitted with an ignition switch, not an ignition lock, for the simple reason that in an emergency the vehicle had to be useable by anyone.
Other mistake: In the episode where Radar is talking to Corporal Hendrix, Radar says that he was thinking about getting a tattoo himself. But in season 3 episode 7 when Col. Blake was giving Radar his physical he had an anchor on his right arm which he said was his new tattoo.
Continuity mistake: B.J. is holding a Korean child who is subbing in for his own daughter when Margaret hands B.J. a piece of cake. Just as it looks as if he is about to feed the cake to the girl, the scene cuts to a full facial shot of Hot Lips, then cuts back to B.J. The cake has disappeared. There wasn't enough time to eat it all, and neither the child nor B.J. is eating. B.J. has no icing on his fingers; it has just disappeared.