Other mistake: Across the show, several times doctors looking at an x-ray picture say things like, "Looks like he swallowed a whole junkyard" or "His belly is full of shrapnel." In fact, shrapnel, being metal fragments, should show up as clear white spots on the x-ray pictures, but none of that is visible in any of the x-rays shown throughout the show.
Factual error: After Radar asks Klinger when his home movies will be ready, Max answers, "Ready whenever you are, C.B." This is the specific punch line to a joke that relates to the actual filming of Cecil B. DeMille's 1956 movie The Ten Commandments, which wasn't released until after the Korean War. (00:16:30)Bob Blumenfeld