The only thing amazing to me is that they let the guy live.
It is probably good to have him for questioning. I think most of these jerks and their associates expect them to either off themselves of get killed.
Maybe, the best thing would be to question him. Get as much info as possible. Make up even more intel that we got from him and then drop him off behind ISIS lines after letting his sick brothers know all the great intel we got from him.
The Frenchies will probably sentence him to ten years in prison and let him out it one.