I think the elevator trim tab conclusion, and the fact that the pilot was unconscious before impact, was known less than two weeks following the incident.
This report just confirms it.
Here is one of my favorite videos (posted in September 2011) which analyzes the event and is meant to be a slap in the face to those who think such things should be banned.
http://www.youtube.com/watch?v=jCBbosq9-RI