Snape isn't evil

[Marianne S.]

No: HPFGUIDX 143784

Lucianam: <snip>
Only one Huge Thing stands in the way of Snape's warning the Order
proving he's good: why didn't Voldemort punish him heavily for ruining
the Prophecy mission? Voldemort must have had reasons to believe
Snape's actions were acceptable. If Voldemort didn't question Snape's
loyalty as a DE because he warned the Order, why should we believe the
only explanation for Snape's doing so is his being loyal to Dumbledore?


Marianne S: 
Where is the canon that shows LV knew Snape was the one that warned 
the Order?