Hussar
Legend
What does willing or unwilling matter if an
act is still unjustified?
Again, where the line of "justifiable belief" comes in is far to subjective to actually prove anything. I can state that I don't believe that there is anything I can do to stop a hungry dragon from eating this NPC. That's a pretty plausible belief. It's a freaking dragon. It just demanded the NPC.
I mean, if the paladin thought he could talk the dragon out of it, and then the first time he does anything other than hand over the NPC, the dragon automatically kills him, doesn't that mean that your belief that the paladin should have done more is completely unjustified?
Basically, your belief that the paladin should do more is based on your reading of the DM and the game - a DM wouldn't just flat out kill a PC because that wouldn't be fun. And, for many tables, that's not an unreasonable belief. At my table, your kibbles.
And, let's not forget, he DID negotiate with the dragon. He negotiated well. The best result he got was a demand for the NPC. Retries on persuasion checks are generally not allowed in 5e. Once you achieved a given reaction from the NPC, that's it. You're done.
So, given the evidence, I'd say it's not an unreasonable belief to think that continuing to delay the dragon is going to give you a better result than what you already got. Time to cut bait is not an unreasonable reaction.