Continuity mistake: Along with Radar holding an anachronistic comic book (the Avengers), the exact issue changes between wide and close shots. One has the older Avengers logo used in the '60s and very early '70s, while the second issue Radar is holding has the newer Avengers logo that just gained currency as the episode was being filmed.
Continuity mistake: When Hawkeye is examining the orphan who is wiggling his tongue, there are two camera angles: one of Hawkeye from the front and one of the orphan over Hawkeye's shoulder. In the first shot, the tongue depresser that Hawkeye is holding is horizontal, in the other it is vertical. This flips back and forth a couple of times.
Continuity mistake: The "KILROY" Hawkeye writes on the window as BJ looks out was in the center with his fingertip. Later, as Hawkeye looks out, the "KILROY" is now closer to the frame, and the lettering is different, a small capital A in front of it, and lines above and below it.
Continuity mistake: In any scenes in the CO's office, look at the windows - they're sometimes opaque, sometimes clear. Also the windows in the OR. Usually semi-opaque, once, they were totally opaque, and made of a thick plastic. This was because it was very cold outside, and Hawkeye used a scalpel to cut them open to let in cooler air.
Factual error: Henry says that every Wednesday, his wife drives up Route 26 with some friends. US. Route 26 starts out in Nebraska and leads to Oregon. The closest thing that could be described as a "Route 26" would be the road leading from Princeton, IL to Dixon, IL which begins 85 miles from Bloomington. The writer probably meant Route 24, which passes about 20 miles north of Bloomington.
Continuity mistake: When Cpl. Hendrix is examined on the operating table, Klinger and Hawkeye admire his tattoos. Klinger asks "do you really think the real Louise is built like that?" and Hawkeye replies, "If she is, I'm in love". Later, when Radar talks to Hendrix, Radar says, "Her face is still pretty, and her legs are the greatest." Hendrix asks, "What about the rest of her?" and Radar replies, "There isn't any." How could Hawkeye and Klinger admire Louise's build if the tattoo was that shot up?
Factual error: Nearing the end of the show, we are told that the Chinese have become involved in the conflict and have attacked with some 300,000 soldiers. This apparently refers to massive attacks by the Chinese starting on November 1, 1950. Although the numbers are correct, the US/UN forces were unaware of the numbers. As late as November 6, the Far East Command continued to insist that there were no more than 34,500 Chinese communist soldiers in country. http://www.history.army.mil/brochures/kw-chinter/chinter.htm.