That "fact" is out there, alright. The real facts (available at http://www.nfl.com/teams/profile?team=DEN) are that Denver's offensive line (except for the center, who lost his starting position this year after being injured before game 5) and recievers (except for Stokley, a distant third in yards) are EXACTLY the same this year as last ... yet this year's QB has a 68.6% completion rate and a 105.8 passer rating, as compared to 46.5% and 72.9 for Tebow.
Except the W-L Orton’s stats with that offense were much better too. But the defense gave up tons of points. Had the defense allowed the same general lack of scoring for Orton they did for Tebow (15 points less) Tim would have never started because Orton is I think 4-1 (maybe 3-2) instead of 1-4.