Not true, at all. If our guys fall into the wrong hands, they're toast. But, we have had soldiers be wounded and separated from their units and be cared for and defended by tribal villages from the Taliban.
Their is a Pashtun code of conduct that predates Christ, called "Lokhay Warkawa. It says in part that travelers (to include warriors) who are seeking aid and shelter, must be given aid and shelter. Tribal Afghans have fought to the death protecting wounded coaltion forces, because that is the code they live by.
You should read a book by Marcus Luttrell called Lone Survivor: The Eyewitness Account of Operation Redwing and the Lost Heroes of SEAL Team 10. It's fabulous, and explains in great detail why Luttrell is alive today - Lokhay Warkawa.
I read it, great book, that is one case. There are a lot of other cases that back me up. Read another book “A Journal of the disaters in Afghanistan”, by Lady Sale Florentina.