The situation described here is different. The battle isn't over, and you can't afford to leave a hostile alive behind you. If you were delaing with a civilized enemy, an answer might be to tie them up and leave them for the MP's to collect later. But you can't afford to try to tie up these people. They may be sitting on a grenade with the pin already pulled, just waiting for you to move them.
Under the circumstances in Fallujah, I can't see any answer other than shooting every enemy, even the enemy wounded.
Hey Joe! Great to see your byline. Great book too, BTW!
(The Justice Cooperative, for those who don't know.)
I see nothing tricky here. Perhaps it is just me.
Some may recall this was a favorite trick of the Japs in WWII. My 1st Cav Dad had no problem with making sure they were Damn well dead. Daddy was Signal Corps. You should see the pictures I have from the Phillipines. Flame throwers got them out of their holes-crispy and dead.