Continuity mistake: During the scene when Torpedo Eight squadron is slaughtered during its attack on Nagumo's carriers, Ensign George Gay's aircraft changes appearance several times. This is due to the different snippets of wartime footage being cobbled together. When the squadron commences its attack, his plane is a Vindicator. When his plane is the last one left, it has changed into an SBD Dauntless. When Gay's plane has been hit and is diving towards the sea, it has become an Avenger. Finally, when his aircraft hits the water, it has become a Hellcat.
Continuity mistake: When the American torpedo bomber attacks the first carrier, it gets shot up and flies past the carrier, crashing into the sea, at which point it becomes a single seat fighter.
Continuity mistake: The same Forrestal-class carrier (60's vintage with slanted decks and full radar suites) is used as the "Hiryu" and "Soryu"...one of which is simply the same film turned left-to-right, including the backwards hull number painted on the flight deck.
Continuity mistake: During the Japanese bombing of Midway, you can clearly see, briefly, battleship masts in the background. Recycled footage from TORA, TORA, TORA.