Ken Timmerman has an article (promoting his new book) in the NY Post about how, on July 25, 2012, a Chinook flying over Kunar was targeted and hit by a Stinger missile fired by the Taliban. Luckily, great piloting and crew team effort landed the bird...hard:
The assault team jumped out the open doors and ran clear in case it exploded. Less than 30 seconds later, the Taliban gunner and his comrade erupted into flames as an American gunship overhead locked onto their position and opened fire.
The next day, an explosive ordnance disposal team arrived to pick through the wreckage and found unexploded pieces of a missile casing that could only belong to a Stinger missile.
So how did the Taliban get their hands on a Stinger that had been signed out to...
Apparently, SecState Clinton knows.