When in the bunker during a bombing raid, the closeups of William Bendix show someone's left hand on Bendix's left shoulder. But in the wider-angle shots, no one is touching him.
When Japanese snipers hid in the tops of trees, they tied themselves into their positions. They did not fall out of the trees when shot.
The score of game 2 of the 1942 World Series was actually tied 3-3 going into the bottom of the eighth inning, not 1-1 as mentioned during the radio broadcast. To provide closure, Stan Musial singled in Enos Slaughter from third to provide the winning run.
In one scene, one of the actors has a Thompson sub-machine gun with a giant ring over the front sight like a sight guard. In real life they don't have sight guards.
Japanese Type 97 grenades were primed by pulling the pin first and then hitting the striker hard against something hard (A rock or a helmet) to ignite the primer before throwing. During the battle at the cliffs, a Japanese soldier pulls the pin in a grenade and tosses it immediately without striking the pin.
One of the Japanese soldiers is carrying a US Krag rifle from 1892.
When the soldiers are listening to the radio report of the baseball game the broadcaster politely pauses every time one of the men makes a comment.
In several scenes, Japanese soldiers are seen firing U.S.made and issued Thompson .45-cal. sub-machine guns, identical to the one carried by Sgt. Hook Malone. In one scene, a Japanese machine gun nest is firing a Thompson mounted on a tripod to make it appear as a light machine gun.
The actor playing a Japanese prisoner falls backwards into the water after jumping from the landing craft when the Marine raiding party lands on the beach. Just then, a wave picks up the landing craft and another actor helps the Japanese actor up, just as the landing craft drops - a very near miss.