Producer Walter Wanger was serving time in Wayside Honor Rancho after he was convicted of shooting Jennings Lang in the groin for having an affair with his wife, Joan Bennett, while the film was being made. Another producer substituted for him so he could complete a contract agreement.
Chinese writing, not Korean, adorns the buildings and signs in Korea in the film. (This is prior to the intervention of the army of Communist China.) While this may seem like a mistake, it is historically correct.
The alphabet now used in Korea is called Hangul, and it was invented in 1443 AD. Three years later in 1446 Hangul was made the official writing system of Korea. Despite this, "Hanja" (Chinese characters used to represent Korean sounds) remained the most-used writing system in Korea for over 500 more years, including during the Korean War.
In South Korea, the Korean War is usually referred to as the "6.25 War" as it started on June 25, 1950.