Snape protecting the Trio

[grace701]

I suppose this scene we won't be able to find out exactly why he is 
doing this when there is no scene in the books stating so.  The only 
time it is stated that Snape was "protecting" them was in the 
beginning of the 'Hermione's Secret' chapter  where Fudge states 
that if it weren't for Snape...yada yada.  And it is mentioned that 
he is going to receive the First Order of Merlin (or something like 
that ;)).  Everything else I've been able to figure out, such as 
Snape and Harry in the hallway.  It has to be that Harry got caught 
or when Snape finds Harry about to go into the secret passage.

Grace