So, what you see is children dead, children turned to stone, and this is the dark side of that fairy tale quality that we see in other parts of the novel that's been coming back in our lectures.
He knew he could not win and chose to spare himself the humiliating details of once-cherished teammates testifying against him, of other evidence rolled out to expose the dark side of the fairy tale.
So I don't think it was unusual for Bartok to pick a revisionist rendition of a dark and terror-filled fairy tale as the libretto for his first and only opera, Duke Bluebeard's Castle.