Factual error: In surgery Trapper John is singing Frank Sinatra's version of "I got you under my skin". Although it was written in 1936, Sinatra did not release it until 1956, after the Korean War ended. The 1936 version sung by Al Bowlly sounds nothing like the version Trapper John was singing, which was mimicking Sinatra's version.
Revealing mistake: When Henry is trying to convince Baker how wonderful the camp is, Henry says that they "had 'The Thing' and 'The Blob' both in one week". "The Blob" was made in 1958. This season of M*A*S*H is set in 1951 and 1952 (and the war ended in 1953). (00:03:55)jle
Visible crew/equipment: After Harper, the JAG, has Trapper and Hawkeye sign and attest to the blood report, when Radar enters Henry's office we can see a crewmember's hand near the floor between the two doors, preventing the closing door from swinging back and forth. (00:22:20)Super Grover