3 missing Death Eaters

[oiramertip]

No: HPFGUIDX 82874

Hi,

I apologize if this has already been discussed.

In Chap. 33 of OOTP, LV talks about the Death Eaters that are 
missing in the graveyard:

" And here we have six missing Death Eaters... three dead in my 
service. One, too cowardly to return ... he will pay. One, who I 
believe has left me for ever ... he will be killed of course ... and 
one, who remains my most faithful servant, and who has already re-
entered my service."

I think it is safe to say that Karkarof is the coward, Snape is the 
one who left, and Crouch is the faithful one.

LV appears pretty definite in saying that Snape left, and that he 
will be killed. 

Has anyone speculated as to what Snape could have done to convince 
LV not to kill and let him back?

Mario