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.
When BG Fellers awaits the arrival of the emperor for the meeting with MacArthur, he is wearing a "Class A" uniform. His right shoulder epaulet end is improperly *above* his collar, rather than the proper placement *under* the collar. During the meeting between MacArthur and the emperor, the epaulet has been placed properly. It is possible that someone might have advised BG Fellers of his uniform mistake, but there did not seem to be sufficient time or opportunity within the flow of the scenes to do so.
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 (8-6-1945). "Fat Man" was used in the second attack, three days later (8-9-1945) on Nagasaki.
In several scenes General Fellers is seen wearing an uniform with ribbon decorations. They differ from what Fellers actually was awarded per the Wikipedia article on him. Specifically in the top row he appears to be wearing a Bronze Star, Purple Heart, and Army Commendation, none of which he was awarded.
In the opening sequence, they show a B-29 departing to deliver an atomic bomb (incorrectly shown as Fat Man, the Hiroshima bomb was in fact Little Boy), and the aircraft is marked with "A 24" on the vertical stabilizer. The Enola Gay had a large "R" in a circle on the vertical stabilizer, and the number "82" written on the aft portion of the fuselage.
Bonner Fellers is shown having a romantic relationship with a Japanese woman. This is relationship is entirely fictional Fellers was married to Dorothy Dysart in 1925. They stayed married until his death in 1973.
In the close up on General Fellers'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".
The USAAF C-54 shown in the beginning of the film bears the postwar, United States roundel with the red stripes added to the white streamers. This did not appear on U.S. aircraft until the creation of the US Air Force, separate from the US Army, in 1947.
While researching his thesis, "The Psychology of the Japanese Soldier," Fellers interviews Gen. Kajima, who mentions America's oil embargo. Bonner F. Fellers completed the thesis in 1935, but the embargo did not happen until 1941.
General Bonner Fellers (Matthew Fox) claims that he diverted bomber missions to protect his Japanese girlfriend's school but his bio states that he was a regular army officer and never a member of the Army Air Force.
On a sheet detailing Aya Shimada, she is listed as Ms Aya Shimada. The salutation of Ms, while it came into usage in an earlier century, did not come into revived usage in the United States until the late 20th Century. Thus it would likely not have been used in a paper prepared during World War II.