When does V understand why Harry lived (was: Plot holes in GoF?)

[isabelle_69au]

No: HPFGUIDX 32369


At the end of GoF LV tells the DEs why Harry survived the Avada 
Kedavra curse - but I would like to know when he figured it out.

We find out why V/Q was unable to bear Harry's touch in PS/SS, when 
Dumbedore explains it to Harry in his hospital bed.  Dumbledore then 
says "If there is one thing V cannot understand, it is love ... to 
have been loved so deeply ... will give us some protection 
forever.".  I take that to mean that V may still not know why Harry 
was able to defeat V as a baby and V/Q in the present.

In CoS, Riddle asks "how is it that a baby with no extraordinary 
magical talent managed to defeat the greatest wizard of all time?".  
Harry tells Riddle that his mother's love protected him, but this 
information never gets back to Voldemort.

If V hasn't worked it out at the beginning of GoF, is it possible 
that fake Moody was testing Harry when he taught him about the 
unforgivable curses - trying to work out what it was about this 
seemingly average kid that had come so close to destroying his 
master.

Isabelle