I suppose that you are from the USA and your family is living there. Imagine that some afghan-controlled drone intended to kill some U.S. soldiers (a legitimate target because they are enemy combatants). But instead they kill your family. If it was a mistake, by the own account of the drone operator, would you still maintain that the killing of your whole family was not a war crime? Would you defend the drone operator in that case? Please notice that at the moment when they were killed, they were just enjoying a picnic in a field, minding their own business, unbeknownst that in another valley a few miles away there was a secret military training camp. I need to hear from you if you honestly think that the murderer of your family would be innocent in that case.