given all the facts that we know right now, i'm inclined to believe that Te'o is super naive. He was hoaxed by someone and it went way too far, so the fake girlfriend was killed off to end it.
I completely believe that he would have made up stories of meeting her to avoid the awkwardness of a bigtime football player having an internet girlfriend.
Either way, this story is fantastic and I don't want it to end. Now there's a football player for the Cardinals that says he met the girl before Manti was in the picture? These twists are great.