> How much we screw up and hit the wrong target is a totally different question from are we killing civilians without regard for them.No, it's not. When assessing weapon capabilities, precision and collateral damage are irremediably linked, with precision including actual chances of hitting the specified target.
In this case the weapon is the "droning process" as a whole; if the process hits the wrong target too many times, its precision is low and hence the likelihood of collateral damage is high.
These casualties cannot be justified as "accidental" once the weapon/process' capabilities and actual limits are clear: it would be like throwing a hand grenade in a crowd to hit a single person and then argue that other victims were "accidental" because the question of explosion radius is unrelated to effectiveness at the center of it.
Drawing this sort of distinction in reality moves the debate from the main question (should we use this weapon, given its known limits?) to other, often-unanswerable ones (how many collateral casualties can be filed as "accidental" while ostensibly respecting moral and legal thresholds?) that inevitably imply the previous question can only be reasonably answered in a certain way.