Let's see, oh, here's a list of non Afghani private contractors killed in Afghanistan.
List of private contractor deaths in Afghanistan - Wikipedia, the free encyclopedia
"As of January 16, 2012, 190 foreign private contractor deaths in Afghanistan as part of the War in Afghanistan are listed in this article. Of these, 54 are Americans, 14 are Nepalese, 13 are Canadians[5] and 13 are Russians. 38 of those killed were private military contractors or PMCs."
So that leaves 152 out of the 190 killed that were non military contractors, aka "civilians", many of whom were aid workers.
I don't have time to count how many of them were killed by Afghani soldiers and police or those masquerading as such, but I know it's more than a couple. Furthermore, several coalition troops have been killed by those soldiers and police they've been training. With several hundred thousand troops circulating through the country in the last 10+ years, statistically someone is bound to be batshit crazy and/or go completely nuts under those circumstances in that time.
Meh. Collateral damage. Shit happens.