The rules only mention that they need to take responsibility for their actions, not that they need to die for it. But it's more interesting like this for me, so I'm glad to hear you say so! It wouldn't do to give a boring option like mercy after all.

[Who'd even choose it? Mallick's self-defense was one thing, but they would've reacted the same if Sayaka had been the one who ended up down there, wouldn't they? There's no sense in letting killers off the hook.]