Faking death is a violation of the GC.
Using a house of worship to store weapons or conduct combat operations is a violation of the GC.
Fake surrenders are a violation of the GC.
All of the above were commonplace in Falluja.
Other wounded insurgents were not shot, because they were not trying to conceal the fact that they were alive.
Weapons WERE recovered in the room (video shows AK-47s being carried out by Marines).
Did the Marine over-react? Maybe. But, what he did must be viewed in context of the environment. What he did may not have been PC, but under the rules of war, it wasn't illegal either.
This Marine will not be charged and will be back in his unit within days.
My regards,
Widewing