First, that sounds pretty cool.
But let me stop you for a minute, please define "plausible" such that it differs from a lowering of hidden hit points, stats, or rolls of the dice.
Thank you.
It sounds like [MENTION=463]S'mon[/MENTION] fudged the cost of Raise Dead with this NPC to be zero.
As for plausible, I'm guessing the case is to give the PCs a break through NPC action (being nicer or moving dumber), or creating in-game content that helps the PCs and does not contradict any other facts of the game.
For instance, the next chest the party searches has a healing potion in it. It wasn't in the notes, but the GM put it there to be nice right then. If it's plausible to be there (because sometimes chests do have healing potions), then he's fudged game content in favor of the player.
Assuming my definition of fudging by game content manipulation is correct, this is why I call the whole concept of not-fudging into question. Because the GM is ultimately making all this stuff up. Either on the fly, or on paper first. Unless he systematically generates it (random tables?), the human bias (good and bad) is at play behind the GM screen.