In the discussion with Admiral Nimitz about determining the meaning of "AF", Nimitz orders the fake message sent to Midway via a courier flight. The message was actually sent to Midway via the Trans-Pacific Cable which was still operating from the west coast of the U.S. to Midway. Due to its distance from Pearl Harbor, there were no daily courier flights.
Admiral Nimitz's office at Pearl Harbor includes a Navy Department flag (blue with the department seal in the center). The setting is 1942, but that seal wasn't adopted until 1957, and the flag not until 1959.
The final scene of the movie pans the Carrier berthed in Pearl Harbor showing "bridle catchers" on the bow of the carrier. Bridle catchers are for catching the early catapult launch rigs from launched aircraft. Needless to say, the Yorktown and Essex class carriers did not have catapults at the Battle of Midway.
Ensign George Gay is shot in the right hand and arm. But, when he is swimming in the water, he is favoring his left arm, and reaching for his flotation device with his right hand. Later, when he is in the water watching the attack, the wounds are gone.
In the shot of the Japanese plans about to attack Midway for the first time it clearly shows torpedoes slung beneath the planes, not bombs. In the immediately preceding scene the Japanese officers discuss whether their remaining planes should be armed with torpedoes (to attacks ships) or bombs (to attack Midway).
When Tom Garth lands his plane after the attack on the Japanese carriers, his face is blackened from the fire in the cockpit. When the crew takes him out of the plane and places him on the stretcher, his face is dirty, but not blackened.
The actor portraying the radio operator aboard the Soryu search plane trying to radio back the location of the Yorktown is also in the group of Japanese sailors aboard the Hiryu watching the other three Japanese carriers burn. These two events are supposed to be happening simultaneously.
During the Coral Sea battle, a crewman shouts that two "Kates" are heading for the bow of the American carrier. However, the two aircraft shown, clearly have a crew of one. The "Kate" (Nakajima B5N) had an elongated canopy to accommodate a crew of three.
When USS Enterprise returns to Pearl Harbor at the end of the film, southern pine and oak trees surround the port. The landscape clearly is not Hawaii, but Pensacola, Florida, home port of USS Lexington at the time.
The jeeps owned by the U.S. Navy are shown with the I.D. letters "USA", this was the army's designation. The Navy jeeps were lettered with "USN" (US Navy), they are portrayed correctly in "Tora! Tora! Tora!"
When the Yorktown is under attack, the carriers are shown shooting at the Japanese with Quad 40mm and 20mm. At this time Enterprise, Yorktown and Hornet were still armed almost "as built." Their armament was composed of 5"/38s, 1.1" and 50 cal. water cooled.
Tom Garth tells his father that he's been assigned to VF-8 (Fighter Squadron 8). When his dad (Capt. Garth) sees him reporting to the USS Yorktown he is shocked and says he wasn't supposed to ship out for a week. This can't be since VF-8 was assigned to the USS Hornet and would have shipped out before the elder Garth did.
In all the overhead shots of the carriers, angled flights decks are clearly visible. Angled flight decks weren't added until the USS Midway's refit, and Japanese carriers were never retrofitted with them.
When the last Japanese carrier is being attacked, Japanese anti-aircraft fire destroys a bomber which explodes in mid-air. The bomber is twin engined (attacking aircraft are all single engined) and German markings are visible on the wingtips. It's unlikely that German bombers took part in the battle of Midway and certainly not attacking allied Japanese shipping.
At one point Admiral Nimitz says, "It's times like these I miss the flatlands." Nimitz was born and raised in Fredericksburg, Texas, in a part of the state known as the Texas Hill Country. According to his US Navy biography, Nimitz left high school in 1905 to enter the Naval Academy. Annapolis was probably the first time in his life that the future Fleet Admiral saw anything resembling "flat lands."
The majority of U.S. torpedo bombers used at Midway were of the type called "Devastators" and the torpedo carried was clearly visible. Most of the scenes used "Avengers" and the torpedo was carried internally and not visible until they were dropped. Some "Avengers" were flown at the battle of Midway.
A title card late in the movie lists as June 6, 1942, which was the last day of the Battle of Midway and the day the Hiryu was hit. In fact, all four of the Japanese carriers were hit all on the very same day which was June 4, with the Hiryu being hit late in the afternoon, not two days later.
The movie shows pilots flying SB2C "Helldiver" dive bombers, such as the one the elder Garth flies immediately before crashing into the end of the flight deck. The SB2C "Helldiver" did not enter service until toward the end of the war and was not available during the Battle of Midway.
In the second air attack on Yorktown, the movie shows two kamikazes hitting the aircraft carrier. There were no kamikaze attacks or intentional crashes into ships in this battle. Yorktown was hit by three bombs in the first attack and by two torpedoes in the second attack.
The first aircraft shown taking off to defend Midway are two Army P-40 Warhawks. There were no P-40s stationed at Midway, only Marine F4F Wildcats and F2A-3 Buffalos. The scene is from the movie Tora, Tora, Tora, showing aircraft taking off to defend Pearl Harbor.
Throughout the attack sequences dive bombers are shown dropping their bombs while in level or near level flight. Dive bombers attacked in steep dives (hence the name). US Navy and Marine Corps dive bomber pilots were taught to dive at an angle of about 80 degrees. Bombs were released at the end of the dive while the aircraft was still near vertical to achieve the maximum in accuracy. The bombers would pull out after their bombs were released.
During the final American bombing attack, a Yamato class battleship is seen abreast of the Hiryu. No ship of this class was present with the Carrier Striking Force. The battleships with the carriers were the Haruna and Kirishima, both of the much older Kongo class. The Yamato, flagship of Admiral Yamamoto, was farther to the rear with the Main Battle Force.
The scenes of antiaircraft fire on the Japanese ships shows American twin five-inch guns and quad 20-millimeter "pom pom" guns. This was because very little footage of Japanese ships survived the war and what did was shot on poor grades of film.
During the second attack on the Yorktown, stock footage shows a battleship blasting a Japanese bomber out of the sky with its 16-inch guns. Those main guns did not have an AA capability nor did any gun above five inches because of the slow rates of fire and the inability to fire above a certain angle.
In the beginning of the scene where USS Enterprise and USS Hornet are leaving Pearl Harbor, it has a shot panning across Pearl Harbor showing an aircraft carrier marked "3" (meaning CV-3 USS Saratoga). But it is not a Lexington class ship (the class of ship that the USS Saratoga belonged to) it appears to be an Essex class carrier that someone has changed the number on (probably CV-9 USS Essex).
In the overhead shots of the carriers the island is on the port side and the angled flight deck on the starboard side. This is backwards and due to film reversal, but this was intentional. These are supposed to be the Japanese carriers Akagi and Hiryu, which had their islands on the port side. Neither ship, however, had an angled deck.
Though the movie shows two Kamikazes hitting the Yorktown, there are no reports of them hitting any ships during Midway. In fact, the long shot of a kamikaze smashing into the island of the Yorktown is actually real footage of a suicide plane hitting a carrier during the Battle of Leyte Gulf.
In virtually every shot of the flight deck looking up at the fighters and bombers overhead attacking the U.S. ships, the anti-aircraft guns show the red paper caps of the blanks rather than pointed bullets.
There were over 20 scout planes sent to look for the Japanese fleet and a large grid was used to plot their movement. The path of the plane that first spotted the Japanese fleet ("Strawberry 5") was circled - before its report was radioed in.
As Ensign George Gay's plane crossed over the carrier, just before crashing, the green plane that goes over the Japanese carrier's deck has Japanese Hinomaru markings on the wing, rather than a blue/gray plane with star markings.
When Yamamoto asks how (Doolittle's) bombing raid was done, the messenger tells him that US land-based bombers were launched from carriers. It would have been impossible for the Japanese to have that information 10 minutes after the attack.
The goof item below may give away important plot points.
When Matt Garth crashes on the flight deck at the end of the movie, it is actually footage shot during Korea, showing a SB2C "Helldiver" striking the ramp before turning into an F9F "Panther" jet fighter bomber as it explodes.