Revealing mistake: When the mayor's wife attempts suicide by stuffing herself with pills, she is lying behind a sofa, only her arm and the pill bottle being visible as she pours the contents into her mouth. In the next shot (a close-up), however, the crown of her head is visible, and it is evident that she pours the pills over the top of her head.
Factual error: Due to paranoid fear of sabotage, all Japanese Americans were interred in camps along the west coast during WW2. So it would have been MOST unlikely for Yamashita (especially considering his military background) to simply walk about freely and to have work as a gardener.
Trivia: The movie was not very popular in the US since it dealt with WWII and Nazis in a very unconventional way (for Americans), but it did enjoy great popularity in Europe.
Trivia: The assassination attempt on Hitler obviously originates from the historical attempt from July 20, 1944, by Oberst von Stauffenberg, as it should have been under "ideal" conditions - except that the bombing occurred in Hitler's command center the "Wolfsschanze," in East Prussia.