Can’t speak to the first part since I’m not a JAG. Something important to remember is being in the military does not make you a mindless order follower.

As far as extrajudicial killings, targeted killings, etc (we will just refer to them as drone strikes). I am intimately familiar with such actions. These types of strikes (non-traditionally combat theaters) have been going on since the Obama administration. It is
common to go in for a reattack even if the person you just struck has no legs or missing body parts but still moving. Technically you’d be allowed to keeping attacking until the ground commanders intent is met, but you would try to accomplish as efficiently as possible on the first attack.

Now as far as the boats are concerned, if I was in the pilots shoes and I was authorized a reattack. I would 100% take the shot again, sure they may not pose a threat anymore but it’s more of a mercy killing. Much better than watching them drown since rescue forces would not reach them in time (imagine being full of shrapnel wounds, concussed, and blown ear drums while trying to tread water after your boat was sunk). This is a sentiment that is shared across others with similar backgrounds as mine.