Other mistake: Charles starts a discussion on the army having forbidden the use of curare. The following chatter is all about how things in the M.A.S.H. OR have slowed after curare was banned, leaving us with no choice but to understand that the ban came into effect during the Korean War. Actually, curare was not approved for use by the U.S. Army at any time during the Korean War. (See "Notable Names in Anasthesia" - J. Roger Maltby, Royal Society of Medicine, Great Britain, pg. 14). (00:00:25)
Suggested correction: The whole point of the discussion is to make it clear that curare was never allowed for use by the US military, however since the majority of the doctors there are not enlisted, they know of curare and how to use it on a patient. At no point is it mentioned that the banned occurred during the Korean war.
While they never specifically say that the ban occurred during the Korean war, at the beginning of the episode, Charles says "Ever since the army forbade our use of curare..." Then at the end of the episode, COL Potter says "It sure is the cat's P.J.s having our curare back." after they get some supply from another non-American unit. These conversations imply that the doctors had been allowed to use curare by the army until this point and the ban by the army is why they aren't using it any more.
Father Mulchahy says "I've noticed the work goes much faster with curare." Father Mulchahy's only experiences in operating rooms are from his deployment at mash 4077 (he mentions he used to work with children before the war), so he must have "noticed" it there. This makes it clear as daylight that curare was used at mash before it was banned.
Revealing mistake: In the supply room, as Hawkeye lights two candles, the room gets noticeably brighter. However, there's too much light for two candles, and his shadow comes from above.
