Continuity mistake: The soldiers takes off from the aircraft carrier in Boeing CH-46 helicopters. In the next scene they are flying towards the target and the helicopters are magically upgraded to the Boeing CH-47 model. The mistake is clearly seen when counting the landing gear on the two types. The CH-46 has a single front landing gear and the CH-47 has a double landing gear in the front.
Other mistake: During the ending scene, when Samuel L. Jackson is walking away from the camera across the lawn, he passes directly between the platoon on the right practicing rifle drill, and the platoon leader giving them orders. Marines are taught to NEVER do this. It is called "breaking ranks", and a Colonel in the Marine Corps would have known this.