Lying or not? Please Help!?

Hi, a friend of mine said that he is doing his Masters (PART-TIME) at McGill Uni (Montreal) and when I looked him up on the student directory, there was NO record of him...meaning his name didn't bring up any matches. I am not sure what to think? Either he is lying OR part-time graduate (Masters) students do not get published in the directory as the regular students do? I'm confused! I even heard that not all the students names are in the 'database/directory' and if so, what determines that? I am more inclined to think that maybe he lied not thinking that I would look him up.