Why Snape Can't Be Evil

[Schumar1999]

No: HPFGUIDX 134047

Alla: <snip>"And he slashed at the air: Harry felt a white - hot, whiplike something hit him across the face and was slammed backwards into the ground. Spots of light burst in front of his eyes and for a moment all the breath seemed to have gone from his body, then he heard a rush of wings above him and something enormous obscured the stars." -
HBP, p.604.

Schumar: I took that "White, Hot, Whiplike Something" to be Buckbeaks wing, not a curse. I don't know exactly why... To me, it seemed that the only hex Snape sent toward Harry was to knock out his wand. No one knew exactly that the prophecy implied that Voldemort himself had to kill Harry -- or wouldn't have Snape kidnapped Harry or something to get him to Voldemort? I think within the gloating that Snape was also trying to warn Harry... or maybe even see if he could remember back about legilimency and know that Dumbledore was instructing Snape to kill him. Dumbledore obviously knew what was coming because a) he 
kept asking for Snape and b) Dumbledore himself stunned Harry to prevent him from interfering with what Must occur. Anyone else agree?