Character mistake: In the showdown scene between the Vietnamese officer and Rambo, the Vietnamese officer empties an entire magazine at Rambo from only about 20 metres away but only manages to hit the ground around Rambo's feet. What was he doing, aiming at his feet? He deserved to get blown up to bits for that effort.
Continuity mistake: In the POW camp, Co Bao is discovered by a guard who points a handgun at her. Rambo shoots an arrow into the guard's forehead, who then falls back against a tree with his cap down low over his eyes. In the next shot his cap is much higher on his head, and the arrow is pointing at a different angle. How could his cap have moved up that far with the arrow holding it to his forehead? For that matter, how could the arrow have moved when it was firmly embedded in the guard's skull? (00:33:25)
Suggested correction: The arrow was able to move because upon piercing the skull, the arrow penetrated the brain, a soft matter that would not hold the arrow in place. The brain matter is much softer than flesh. Imagine shooting an arrow into a watermelon. It is not fixed, but moveable.
But the point of the arrow is sticking in the tree. If it wasn't the guard would have fallen to the ground. So it shouldn't have moved.
Factual error: It is completely implausible that Rambo, an experienced green beret would be careless enough to get his gear caught in the plane while jumping out. Also even if he had gotten got, soldiers carry their gear in different layers that are quickly releasable via strap or clip just in case they do get stuck. Rambo would not have gotten stuck, and if he did he could detached his his gear easily and without all the drama.
Suggested correction: Isn't it possible Rambo did this himself so as to get rid of all that useless crap they had given him? He had already stated the mind was the best weapon...why rely on the hi-tech stuff they packed off with him. Not only that but isn't it also plausible that in amongst it could have been a tracking device of some sort, and he didn't want to be tracked?