Lol. Well a CG could be the particularly harsh judge...
Take all the stuff, wake the bound captive, give them a grievous leg wound and say "Now don't do it again!" Then leave them out in the wild.
*Tumbleweed*
As they hobble in a perhaps safe direction, they really better hope they don't get orc rapists on their random monster encounter.
I find being entertaining keeps you safe from the dm's wrath, an unfeeling psycho, not so much.
(This is an adequate example of the pedantry alignment systems cultivate.) The morality in such a situation can be relative—even for a staunch paladin: is justice meted out? Has the punishment of being brought to near-death been fair enough? If so, a certain sort of compassion might hold that the chance (however negligible it may be) for a [vaguely "evil" humanoid] to recover from his disadvantaged situation is suitable magnanimity. But so can another character holding to egalitarian redemption be compelled to save each enemy; pragmatic individuals could rationalize "mercy killing" to prevent any future resurgence. These are all decisions which, by my thinking, can be angled as 'good'. Identifying a character's ideologies is the only sure method by which a DM can sufficiently arbitrate a reasonable, tailored decision. Unfortunately, there are no easy semantics to absolutely satisfy your question—or any such situation playing around in the alignment interpretations.
How characters respond in a situation where lives are in their hands isn't pedantry though, it is a chance for role-playing and a moment to see what characters are made of.
If in doubt, check alignment, think on what a character would do, go with it. If you are acting like another alignment, there is a slow change to this alignment if the dm wants to implement that. I've found it to be that simple, but, players have also tried to justify to me, not acting at all like their alignment (e.g. NG gnome starts talking and acting like a genocidal fascist. er... wtf? A long way from "pure" good).