How do we know that the part of the soul that was left in Voldemort fled his body in a cloud of black smoke? I cannot ever remember this to be canon. Nobody knows what really happened, except Voldemort.
What I do remember is that Quirrel was in Albania and got his turban after fighting some inferi.
So, what goes against the theory that the Voldemort part died and the last created Horcrux activated? We know from CoS that they can a life of their own, they seem to be fully functional.

 

Do you think some Horcrux was activated when he tried to kill Harry, and therefore isn't functional anymore?

I mean, do you think the stuff fuels his soul, so it doesn't die, or they're like "charges", and once used are useless?

 

who cares, one thing for sure, "THE GOLDEN TRIO" god i hate that name, wont be able to destroy them cause they are DROP OUTS. they will die most likely because Ron does some stupid thing as usual.

 

it seems more logical to me that the horcruxes bind voldemorts soul to the mortal plane
i've read several stories where they kind of 'activate' but it just doesn't seem to be right.
if they were pieces of his soul that would activate (like backups or saves on a computer system) then he should only have the memorys/knowledge of the time he created it (young riddle had only those in cos) but since he seems to remember what happened at the potters (in ps) i'd say they keep his soul from moving to the afterlife

 

My thinking was always similar to sal's. I assumed that all the pieces of his soul were tied together somehow. Since AK doesn't destroy a soul (where as something like a Dementor's kiss arguably does) his soul is simply ejected from his body just as it would have been had he completely died. Since the soul was tied down to something else, he doesn't move on and has the ability to come back. Now, despite the fact that it is poorly planned out and makes little to no sense, I think her thinking was that when you destroyed a Horcrux vessel the soul part inside is destroyed (instead of remaining tied to the other pieces and either floating as nothingness with thought, like the part that was ejected from his body or simply going back to Voldemort's body)

 

All that theory implies that the soul left in Voldemort is somehow more than just a part. If the AK kills a soul, it would kill a part of a soul as well.

So my reasoning was that if Voldemorts body had just a part of his soul, he is essentially a living horcrux. So killing (AK) his last remaining soul part activates or frees the next last part. A kind of chain, in backwards order.

So the original Voldemort part really died (because it was killed) but in the cave in Albania the horcrux released the next soulpart in the chain. That would also imply that Harry is definitely no Horcrux and explain why it took him so long to get back to britain, possessing snakes and such. He had to sustain himself and couldnt just float somewhere.

 

Voldemort pretty much flat out says that his "soul" in his body didn't get destroyed with the AK. He goes on some rant at some point explaining how he was cast out of his body to wander as less than a spirit, but was still alive. It certainly didn't sound as though a piece of him died and he was transfered to another part of his soul. In fact, from the way JKR talks about Horcruxes, he didn't create 7 so that he could be killed 6 times and still be fine. Rather he did it for purely Arithmatic reasons.