Upon further reflection, it occurs to me that these situations are exactly why the Geneva Conventions[0] require combatants to have (a) uniforms, and (b) a command structure:
(a) prevents someone low from disingenuously stopping the buck by claiming "tweren't no orders; I'm acting on my own"
(b) prevents someone high from arguing as Uber does: "you see, we're not a traditional army that gives orders to our fighters — we just provide a service that matches attackers and targets online, and really, anything bad that allegedly happened was only between those two parties"[1]
[0] if we're not doing these anymore, just go ahead and tell me "the future is now, old man", and I'll take my mutterings to the pétanque piste.
[1] > "Once the rockets are up, who cares where they come down? That's not my department," says Wernher von Braun —TAL