Gun Related Question:
How easy is it to differentiate between the bullets fired by guns used by our Marines and the enemy in this situation? I would assume they are using AK-47s, mostly.
The holes in the walls and or bones (if the bodies are exhumed) will be of distinctive size.
As many have pointed out, this won't mean jack anyway. The country overflows with AK-47s and plenty of insurgents have AR-15 or similar. In the end, the Predator video and the testimony of the Marines will determine what actually happened.