We Were Soldiers (2002)

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)