Now I am convinced: Either Snape is not completely evil or Rowling has made a mighty slip. Snape had the perfect opportunity to immobilize and kidnap Harry, but he didn't. He's not stupid. If he were truly evil, he missed his golden opportunity to hand Voldemort exactly what he's been wanting.
Good catch! I never thought of the kidnap angle.
Oh...that is good. Maybe they thought he would slow them down? They can't run and hide as easily dragging a 100+ pound person with them. Or Snape slipped up.
Remember that Snape saved Harry once. I think that DD was right that he had reason to believe in him. I also think that it was out of compassion that he took the oath to protect Draco Malfoy. Snape is a nasty man, but I still think that it's a ploy to fight the dark side. Else why would Snape himself be applying for the Master of the Dark Arts position that you know who wanted?
Snape also stopped Harry from using one of the Unforgivable Spells, don't forget. He also saved Harry from the Death Eaters.
He would have had a hell of a time getting him down from the Astronomy Tower undetected with all the OOTP and DA members at the foot of the stairs.
Immobilze, maybe, but not kidnap. He was rushing out with Malfoy (which was priority one because his life did depend upon it) and they were apparating once off the grounds. Snape would have had to forcing teleport someone against their will, which doesn't sound like it would've been an easy thing to do.
TS
The part that puzzled me was Snape yelling at others not to kill Harry on the Dark Lord's orders. Hadn't Voldemort shown, at the end of Order of the Phoenix, that he no longer had any use for Harry after the loss of the prophecy, and that he was prepared to kill him? After all, Voldemort has to get Harry killed if he is to survive. There is an interesting essay on line at http://www.livejournal.com/users/garlandgraves/3409.html (sorry I don't know how to post a link) where the author discusses Snape's guilt or innocence.
I keep wondering about the sorting hat (another relic of Gryffindor, the sword isn't the only one); Lily Evans, whose past seems to be coming up now; and the reference to "Peverell" on Marvolo's ring. Has that name come up before?