When General Fellers arrives at the Dai Ichi the first time, and gets out of the jeep, the badge on his hat is straight. As he is coming up the steps it is crooked, tilted towards his left. When he stops and turns around to look at the Imperial Palace across the street it is straight again.
At the end of the film, a summary of the main characters states that General Fellers was demoted to Colonel by Dwight Eisenhower. Eisenhower in fact had nothing to do with Fellers's reduction in rank - this was an administrative reduction at the end of World War II when over 200 Brigadier Generals holding temporary rank were reduced to the permanent rank of Colonel. The reduction was not punitive, nor unexpected, and quite normal for the demobilization procedures of the time.
In the opening sequence the film makers use archival film showing an atom bomb being loaded into the bomb bay a B-29 for the attack on Hiroshima. The bomb shown is "Fat Man" and not "Little Boy" that was used on the attack on Hiroshima (8-5-1945). "Fat Man" was used in the second attack, four days later (8-9-1945) on Nagasaki.
In the close up on General Feller's typewriter upon which he is writing his initial report to MacArthur, he is seen typing "Pearl Harbour", using the British spelling. An American general would have used the American spelling and typed "Pearl Harbor".