Wormtail's silver hand

[justcarol67]

No: HPFGUIDX 168297

Here's a fanciful scenario to entertain the Snape-lovers (though
really, it's about Peter Pettigrew):

Fenrir Greyback is attacking Harry as he did in HBP. Snape, in deep
cover as a DE, surreptitiously takes Rat!Wormtail out of his pocket,
whispers, "Now!" and tosses the rat onto the ground next to Greyback.
Wormtail transforms into a man and grapples with Greyback and receives
his death wound from Greyback's teeth but at the last second kills
Greyback with his silver hand, fulfilling his life debt and ridding
the WW of one of its most revolting and dangerous enemies. (Exit
Snape, with his role in the incident undetected.)

Okay, it probably won't happen exactly that way, especially the Snape
connection, but surely both Peter's life debt to Harry and his silver
hand are among the clues that JKR planted in the earlier books, pieces
of Peter's character arc that will come together in DH. We know that
the silver hand won't be used to kill Lupin (JKR has already answered
that question), but how else might he use it? Does anyone else think
that the silver hand and the life debt are tied together? If so, how?
If not, why not? If the silver hand isn't a weapon for slaying
vampires, erm, werewolves, what else might it be?

Carol, remembering Peter crushing the twig with his silver hand in the
graveyard scene and expecting him to crush something living in DH