Question: When Professor Snape confronts Draco for avoiding him, he is able to tell that Draco is using Occlumency to block his attempts to look into his mind. Therefore, wouldn't Voldemort know if Snape has ever used Occlumency to block him out, and be suspicious of him?
Captain Defenestrator
22nd Jun 2014
Answer: Two possibilities: One: Voldemort didn't question Snape's loyalty and never bothered to look into his mind to see if he was using Occlumency. Two: Since Snape is operating as the Death Eaters' double-agent in the Order of the Phoenix, it would be practical for him to be using Occlumency at all times (which would have the hidden advantage of not being able to let Voldemort see that he is, in fact, a triple-agent loyal to Dumbledore).
Captain Defenestrator