All the enemies are dead except the boss who says he surrenders, what do you do?

[Quertus]

You are ignoring that unless you are specifically statted into it, taking people alive is much harder than subduing them with lethal force.

The core disconnect seems to be a difference, intentional or not, in the interpretations of how the scenario arose. In my interpretation, the reasonable assumption for how it happened is if taking the minions alive were unreasonably difficult and presented undue risk. In your interpretation, the paladin and party slaughtered the minions just 'cuz. While the latter is more common from the perspective from players not caring about morality, the former is much more likely from an in game perspective.

That sounds very much like a CaS vs CaW issue: CaS assumes a sporting challenge, while CaW says "what's there is there" & it could be anywhere from a cakewalk to impossible. As a CaW corollary, "bandits" are usually at the *low* end of threats that adventurers face, making them rather easy ("wade through them like they were humans" easy) for most adventurers (let alone average "past" characters, who have presumably "completed the campaign").

So, yeah, outside of CaS contrivance, *most* characters / parties should find *most* bandits somewhere between "easy" and "trivial", and should have no excuse for their wanton murder.

Most of *my* characters would murder them unapologetically nonetheless, because I don't play many good characters any more. (Not because I dislike questions of morality, but because I'm enjoying looking at them from perspectives that are very different from my own.)

EDIT: and several of my good characters not only would but *have* taken the hard road, and subdued highly threatening bandits, at the risk of their own personal safety or even at the risk of a TPK. Nobody said that good was easy.