Twelve innocent "friendly fire" deaths in Afghanistan, is this just the price of war?

Tragic as this is, in war. all is fair, sometimes things happen. i don't think it was so much incompetence as it was a faulty guidance system. once the rockets are air born they pretty much go where they are supposed to, yet there are times when a malfunction happens. my opinion. i do not think this was deliberate. to fully understand the war in iraq. or Afghanistan. you would of have to been there. these men and women risk there lives day in day out.so If a rocket or two misses its intended target. well its just the cost of war.