One thing I worry about in warfare is that some enemies have less work to do because they have a different moral compass. Take a terrorist organization for example. If they build a similar drone it does not need to identify armed people, only people or even just movement. That is a much simpler problem to solve. If they can get a drone to their enemies it can kill indiscriminately.

If the enemy has few people in the area or they are willing to die for their cause, their robot doesn't have to worry about who's armed and who isn't.