On the trivial and the profound.

[justcarol67]

No: HPFGUIDX 165661

Bart asked: 
> 	And why didn't he tip off the DE's that Harry wasn't coming?
> 
Carol responds:
I think you're forgetting the mind link. Voldemort knew that Harry was
coming. To tell the DEs that he wasn't would be an easily detectable,
easily traceable lie, and fatal to Snape. Better to let the DEs come
and send the Order after them. And, of course, Snape knew that
Dumbledore was going to 12 GP, and had told Sirius Black to stay
behind and inform him of the situation. So Snape "slithers out of
action" again, not joining the DEs on the pretense that he was ordered
not to do so (he would tell LV that he didn't want to blow his cover).
Besides, if he'd told the DEs that Harry wasn't coming, they wouldn't
have been arrested.

Carol, thinking that it's a very good thing for Snape that Narcissa
and Bella don't know who tipped off the Order of the Phoenix and
wondering if Voldie suspects