Hmm, I think your anger is somewhat justified, considering what he did.
But to me it's clear as swizzik mentioned, that he just isn't that interested in you, but more interested in his own pursuits, as are many, this is only one possible reason though, another is he might just have matured a bit, remembering what he did and is talking to you out of guilt, probably not being able to bring himself to apologize. Who knows, maybe he's just shy, you might not forgive him, is what he could think.
I think you should straighten things out with him by talking, but carefully so, he might not even remember or think of it as you do.
Also I'm not saying you should ignore him completely, I may have phrased it carelessly, just not interact as much, if possible. I still think that talking with him is better since you're going to be seeing him more often thann you average Joe.
(might be the reason yeah.)