Although it can be seen as an embellishment by the filmmakers, Bruno Gaido's daring shooting of the damaged Japanese bomber that was about to crash into the USS Enterprise is genuine. All details, from his jump into the cockpit to the Japanese bomber almost hitting the deck and clipping Gaido's plane, to the exact words of his promotion by Admiral Halsey, are historically accurate.
The wreckage of the Akagi and the Kaga were found the month before the film's premiere.
The film highlights the faulty Mark 13 aerial torpedo used by the US Devestator at the time. Even before the war, the Mark 13 was shown to be faulty with most test torpedoes either sinking, running on the surface, or just failing to launch. Studies later found that many torpedoes were damaged upon impact with the water, namely the propellers and the torpedo head. It took two years of testing and re-evaluation before the Mark 13 became a reliable weapon by incorporating a shroud to protect the propeller fins and adding a drag ring to the torpedo head to cushion the impact. The drag ring was made of wood and would break away upon impact. During Midway, only a single Mark 13 found its target and detonated. It was dropped by a Catalina float-plane and hit the oil-tanker Kiyosumi Maru. The explosion ripped a 33 foot hole in the ship's bow but the Kiyosumi Maru survived and continued on with its mission.
The Japanese admiral Yamamoto expresses his regret over the Pearl Harbor attack, making the famous quote "I fear all we have done is to awaken a sleeping giant, and fill him with a terrible resolve". Yamamoto said something similar in other films about the Pearl Harbor attack, Tora! Tora! Tora! (1970) and Pearl Harbor (2001) (which omits the second part of the sentence). Despite the persistence of this quote in movie history, it has never been officially attributed to Admiral Isoroku Yamamoto; no one heard him explicitly say it, nor has it ever been found within any of his writings. Yamamoto had indeed withdrawn to his room in a depressed state following the attack, but it was reportedly because the Japanese Foreign Ministry had failed to declare war on the USA prior to the assault, which made Yamamoto's actions an unprovoked attack rather than a military engagement. Having lived in the US for a time, he knew that attacking without having first declared war would violate the American sense of "Fair Play". Because of that, their response to Pearl Harbor would be much more severe.
Best's lung problems were caused by an element of his rebreather overheating, which created caustic soda to be generated. The rebreather contains a filter that removes carbon dioxide from expelled breath, making it possible to "re-breathe" expelled oxygen. This is supplemented by another tank containing oxygen to make up the difference. Best had contracted tuberculosis in his youth but it had remained dormant, contained in nodules that were sealed over in response to the initial infection. The caustic fumes penetrated these nodules, releasing the tuberculosis. He was later treated for it and cured. While his lungs had sustained some permanent damage, he was eventually returned to good health.