Goofs

When Doug takes a crow bar and breaks the lock with it, he tosses the crowbar on the ground outside the door and opens the door and steps inside, The next scene when he steps inside he is holding the crowbar in his hand and places it on some boxes.

After Tony and Doug split up, the Japanese lieutenant takes position to shoot at Doug with the water's edge behind him, but in the next shot the water seems to be much closer to him.

When the grenade lands at the feet of Lt. Nakamura, its position relative to his feet changes multiple times.

Doug tosses a Japanese hand grenade after pulling the pin, and it explodes. In order to explode, Japanese grenades of WW II required that they be armed first, by forcefully pushing down on the vertical striker after pulling the safety pin. This was usually accomplished by the soldier banging it against his metal helmet. The grenades thrown in this installment would never have exploded, nor would the booby trap set by Tony and Doug have worked. Interestingly, Doug does properly arm the final grenade that he throws at Nakamura from the cave entrance.

The General says, and they use to get a fix, that two of the ships are the USS Missouri and Illinois. The USS Illinois was never completed as it was decided that a different class of ship was more highly needed for the war effort.

Dr. Nakamura states that his son was a kamikaze pilot, ordered to attack the battleship Shongas. But there was no such battleship. American battleships were named after states, e.g. the USS Missouri. Also, kamikaze pilots were not ordered to attack specific ships, since in practice that would have been virtually impossible.

At the 34:45 mark when Tony is leaning against a boulder to catch his breath, the boulder moves several times from the pressure of his weight.

Lt. Nakamura takes a machete into the jungle to cut two bamboo kendo staffs, but when he returns he no longer has the machete. A trained soldier would not leave a weapon behind, especially a soldier who is at war.