SS question - Quirrell

[pj655123]

I was watching the SS Movie today and something hit me.  I've been 
reading alot of chatter recently on the Book group about Snape being 
a "double agent" and at the end of SS [the movie] when he's at the 
mirror with Quirrell, he mentions that Snape tried to save him, and 
Snape suspected him of wrong doings, etc... now, at this point, 
Voldemort was sticking out of his head, so naturally he would have 
heard every word...so wouldn't this now put Snape in jeopardy as a 
double agent, as his "cover" is now blown? Not sure if this question 
belongs in the "movie" or the "book" group, as it overlaps both, 
but, if you have any comments, I'd like to hear them!
PH