Klinger is blamed for the salmonella epidemic because he procured the turkeys that caused it. However, salmonella is caused by eating improperly cooked turkey, making it the cook's fault. This would have been known to even a well-read layman at the time, let alone a doctor like Colonel Potter, who joins the camp in blaming Klinger.
The treatment of salmonella poisoning has for decades been intravenous replacement of fluids lost through vomiting and diarrhoea, however, no one in post-op appears to be receiving them. Secondly, it rarely requires antibiotics.
Hawkeye refers to BJ as a nerd, but the term "nerd" was only invented in Doctor Seuss's 1950 book If I Ran the Zoo and only began entering regional usage in 1951, when it meant someone who was a square. It didn't really become common until the 1960s when it morphed into its common modern usage, which is the way Hawkeye used it.
The boom microphone shadow can be seen when Hawkeye, BJ, and their "captive" stop to help an old wounded man.