Deliberate mistake: Although the first account of what happened in Zhao isn't completely true, the arrows penetrating the calligraphy school are sometimes flying at angles that make their trajectory impossible, such as arrows flying perpendicular to the ground or even flying upward.
Deliberate mistake: In countless shots showing Japanese, and some shots showing Americans, being shot, take notice of the ground that they stand on. Almost every time a bullet(s) will hit below them at their feet, yet they still fall dead. In some shots even, there is a continuous line of shots from a single shooter, hitting the ground, yet numerous Japanese soldiers fall dead.
Deliberate mistake: During the last assault against the hill, a duo of helicopters is mowing down the Vietnamese soldiers with miniguns. In one shot, you can see one chopper coming up behind a tree, all guns blazing. However, the tree, which is in the way of the helicopters right side minigun, remains totally untouched, although, looking at the carnage the guns do to the Vietnamese soldiers, it should have been reduced to toothpicks. (01:51:00)
Deliberate mistake: The entire time they spend in the trench, before they attack, Quinn has a white sheepskin jacket. It rains throughout the film yet with all the mud about you would think in about a day that this jacket would turn dark brown. It is still fairly white even when Quinn dies.