DDM!Snape clue

[houyhnhnm102]

No: HPFGUIDX 148412

Carol:

> Tonks adds, "We just let them pass. We thought they were being
chased > by the Death Eaters--and next thing, the other Death Eaters and 
> Greyback were back and we were fighting again"--this is the point at 
> which Greyback attacks Harry--"I thought I heard Snape shouting 
> something, but I don't know what--"
[...]
> Snape does shout "It's over, time to go!" to the DEs just before he
> rounds the corner, but these words are shouted *before* Greyback and
> the others join the fray, not *during* it like the Petrificus Totalus
> spell.

houyhnhnm:

Your analysis of the timing of what Tonks heard provides some concrete
evidence I hadn't thought of for Snape's being the one who cast the spell.

I believed it was Snape mainly because it struck me as odd that the
caster of the spell was not identified.  I can't think of another
instance in any of the books, even in all the confusion of the battle
in the DoM, where the caster of a spell against a person is not
identified.  That and the fact that Harry has a very poor ear for
voices.  It took him a year to realize that it was Dumbledore's voice
he heard when Petunia received her howler.

As to why Snape would cast a verbal spell:  Maybe he wanted Harry to
hear him.  CH3ed provides Snape with a credible excuse for the other
DEs, should he need one.