Gleam of Triumph: Protection backfiring on Voldemort?

[jinsler3]

No: HPFGUIDX 98387

Dumbledore's gleam of triumph at the end of GOF remains mysterious
even now that we know both the prophecy about Harry and Voldemort and
more about the connection between them. The gleam came right
after Harry explained how Voldemort used Harry's blood to transfer
Lily's protection into himself, enabling him to touch Harry. Why would
this prompt such a small but positive response from Dumbledore? As a
master Dark wizard, Voldemort should know all of the risks of using
another wizard's blood in such a way. It seems unlikely that using
Harry's blood would make him any more mortal than any other wizard's
blood, and if it made Voldemort particularly vulnerable to Harry, he
would never have dared to duel Harry as he did immediately after his
resurrection.

I believe that Dumbledore's tiny gleam of triumph came not because
Voldemort merely used Harry's blood but because Voldemort
foolishly put Harry's protection into his own veins. The sacrifice of
Lily Potter was part of the ancient magic that Voldemort despises and
underestimates, so if he made an error in his resurrection, it would
involve this. Logically, it should be incredibly dangerous for a being
like Voldemort to take such a powerful love-based protection into his
own veins. Dumbledore understands the ancient magic much better than
Voldemort and may have realized that the protection might turn against
Voldemort, literally consuming him from the inside. Perhaps (venturing
 even deeper into the realm of speculation) if Voldemort touches
someone else who strongly loves or is loved by Harry, the protection
will awaken and destroy him. But this may be an unlikely event,
explaining why the gleam was short-lived; also, even if the protection
consumes Voldemort's body, his spirit may still survive until Harry
directly does away with it.

"jinsler"