Draco's task (For Magpie and those who agree with her)

[justcarol67]

No: HPFGUIDX 157771

Carol earlier:
> Draco would fix the cabinet, allowing the DEs into Hogwarts. The DEs
> would set off the Dark Mark over the Astronomy Tower, fight off or
kill anyone who got in the way, and force Draco to do the task.
(Unknown to him, at first, they'd kill him if he failed.)
> 
> 
Orna responded:
> Actually, Draco did fail – and we don't see any hint of them trying 
> to kill him. They insist upon Draco doing it – holding Greyback 
> back, but nothing there about killing Draco. They want Snape to act–
>  perhaps as Draco's teacher convince him, or help him to do it. But
>  as soon as Dumbledore is killed – nothing more there. <snip>

Carol responds:

There's "nothing more there" because Snape says "It's over!", snatches
Draco by the scruff of the neck, and orders everyone off the
tower--not to mention that he's sent Dumbledore over the ramparts, so
there's no body for Greyback to ravage.

The DEs are clearly under orders to let Draco kill DD, but only
Brutal-Face (Yaxley?) has any inclination to follow or enforce that
particular order. Greyback is slavering to eat Dumbledore for "afters"
and the brother and sister (the Carrows?) seem eager for the action.
They want to see Dumbldore dead. What would have happened if Snape
hadn't entered the room is unclear, but since Draco can't kill
Dumbledore, they would either have had to coerce him (through an
Imperius Curse?) or kill Dumbledore themselves. Draco has been under
death threats to himself and his family since at least April, and the
DEs would have had to decide what to do when it was clear that he
wasn't going to cooperate. Unless, of course, Dumbledore died from the
potion first, in which case, they'd still be saddled with Draco.
Kidnapping Draco with the Order members waiting downstairs was not an
option. They'd have had to kill Draco and Dumbledore, too, or face
Voldemort's wrath themselves. 

Snape's entering the room saved them from making that decision. They
expected him to do it, and so, apparently, did Dumbledore. Only Snape
could get Draco safely off the tower and the DEs out of Hogwarts. Only
he could keep Greyback from eating Dumbledore for "afters." And only
he could make sure the DEs left the tower before they discovered Harry
under the Invisibility Cloak or he charged out to fight them.

Carol, who thinks that terrible as the consequences of the UV were, it
would have been even worse if Snape had not killed Dumbledore himself