In defense of the Snape apologists :-)

[vmonte]

No: HPFGUIDX 136021

Mari Wrote:
The ones I can think of I am setting out below (I know these
would have been brought up before). I summarised some of this
in post number 134540.

1) Saving Harry's life in PS

vmonte: 
If you recall Snape did not know that Quirrell was working for 
Voldemort during SS/PS. Voldemort kept Snape in the dark. 

Page 28, HBP, U.S. edition:

"I think you wanted to know why I stood between the Dark Lord and the 
Sorcerer's Stone. That is easily answered. He did not know whether he 
could trust me. He thought, like you, that I had turned from faithful 
Death Eater to Dumbledore's stooge...As it was, I saw only greedy and 
unworthy Quirrell attempting to steal the stone and, I admit, I did 
all I could to thwart him."

Remember Snape had a cushy and safe job at Hogwarts while the other 
DEs were stuck in Azkaban.

Page 27

"I had a comfortable job that I preferred to a stint in Azkaban." 

Mari:
2) Choosing to go after the trio to the shrieking shack, to protect
them from someone he believed was in league with Voldemort,
in PoA.

vmonte:
Well, this is a matter of interpretation. I see a teacher that is 
more concerned with exacting revenge and getting accolades, than a 
teacher who is worried about his students. 

Mari:
3) Trying to convince Fudge in GoF that Voldemort is back, when
Voldemort didn't want anyone to know this.

vmonte:
Moody had already threatened to tell dumbledore that Snape had it in 
for Harry (I don't think that Snape knew that Moody was Crouch Jr.).
Snape probably felt that he had to prove his loyalty to Dumbledore.

4) Alerting the order to what was going on in the Department of
Mysteries.

vmonte:
He took his sweet time didn't he. Funny how he never shows up to 
anything. Where was he during the fight? Maybe he was afraid of 
blowing his DE cover you say? He's the Potions Master no? He's got 
all kinds of potions locked in his room doesn't he? And with all the 
polyjuice that seems to be floating around Hogwarts you would think 
that Snape would have some to spare for when he needs to go somewhere 
in disguise. But I guess not. 

Vivian