Has anyone else wondered about the parallel that JKR set up between the werewolf "prank" and Snape's death scene? Think about it. JKR has Snape killed in the Shrieking Shack, in a surprise attack by a malevolent Dark creature that rips his throat out, and Snape's efforts to defend himself are futile. Isn't that exactly what would have happened with the werewolf, if James had not intervened?
What did JKR mean by that? It must have been deliberate on her part. Did she mean that Severus cheated his Fate the first time, but Nagini finally made it right in the end? If so, that's a really chilling thought!
(Please excuse me if I've screwed up this post. I'm new to this sort of thing.)