Killing is not necessarily murder and to defeat is not the same thing as to kill.

[Bruce Alan Wilson]

No: HPFGUIDX 157131

--- Lady Lawyer <mouthpiece49 at ...> wrote: 
<snip>
> by the way I don't think that killing someone in
> pitched equal battle is the kind of "murder" that
> will split your soul. I think the soul splitting
> murder has to be with extreme cruelty. Else every
> soldier would have a split soul.
<snip> 

Cassy:
> Well, there's this nice thing called "Vietnam syndrom"
> (or "Afgan syndrom", etc, depending on the country and
> time period). I think that qualifies as split soul in
> a certain way. 

BAW:

AKA 'shell shock', 'combat fatigue', and 'post traumatic stress 
disorder'.  My father suffers from it as a result of WW II, and 
my grandfather had it from WW I.  

JKR says that to create a horcrux one must commit a murder, but 
not all killing is murder!

My legal dictionary defines murder as the unlawful killing of a 
human being with malice aforethought.  Not all killing is murder.  
Killing by accident, or in a sudden fit of rage, is not murder; 
killing in self-defense or in defense of another is not murder.  
That is why we have such concepts as 'manslaughter' and 'depraved 
indifference homicide',  'criminal negligence', and 'justifiable
homicide.'

Also, note that part of the definition of murder is the killing 
of a HUMAN BEING.  It might be argued that Voldemort is no longer 
human.

Hence, even if Harry ends up killing Voldemort, he won't 
necessarily be lost; but there are other ways of 'defeating' than 
killing.  What if he is able to strip Voldemort of his magic, so 
that he must live out his days as a Muggle?  Or if he completes 
Voldemort's transformation into reptilian form, so that he must
live out his days as a snake or lizard?