Snape's Attack on Flitwick

[Kristen]

No: HPFGUIDX 139516

Jen wrote:
[snip]One suggestion for Snape Stupefying Flitwick is when Snape 
heard DE's were in the castle, he knew he would have to assume his 
DE-persona and didn't want Flitwick following him and interfering if 
he appeared to be on the DE side.

Hexicon:
I like this one!


Jen:
[snip]
> 
> And there's more mystery: Snape is *sleeping*. Since when does he 
> ever sleep? Mr. Prowl-Around-The-Castle guy? But Dumbledore 
> confirmed it when he and Harry arrive on the tower: "Go and wake 
> Severus." Now either everyone knows Snape goes to bed right after 
> dinner and sleeps for a few hours, then is up all night guarding 
the 
> castle, or DD (and thus McGonagall) knows that on this particular 
> night, Severus is sleeping because DD made it so by a potion or 
> spell. A spell is more probable, Snape could sniff out a potion. 
> 
> The only possible motive for DD to do this, and it's tenuous at 
> best, would be if Snape was trying to actively keep Dumbledore 
from 
> going after the cave Horcrux. Maybe Dumbledore told Snape he'd 
found 
> another Horcrux and was planning to take Harry with him and Snape 
> argued, sneering about Harry being a liability. So DD resorted to 
a 
> sleeping spell for just that night. The argument against this idea 
> is DD would want Snape fully functional every time he leaves the 
> castle.
> 

Now Hexicon:
Perhaps DD told Snape, in effect, "Severus, I'm going on another 
little "trip," and you remember what happened after the last one 
[ring, burned hand], so please get some rest, as I may need you to 
help me when I return."  As for McGonagall, maybe DD told her not to 
include Snape on that particular patrol shift.

Or do we know that Snape didn't know DD was gone?