Was he his coach?
Yep, freshman through junior years. Then when Mullen left for MSU, they brought in Scott Loeffler to help clean up his mechanics.
I still remember the graphic where they freeze-framed him throwing the ball his freshman year versus his senior year. Exact same delivery. Maybe the issue was Tebow, but given the fact that Mullen had three years to fix his throwing motion and didn't, I don't see that as a positive for Mullen.
Once DBs got film on him to recognize that once his windup began, you could break on the ball, he was done. Couple that with him reverting to holding the ball lower and reaching all the way back with it, not only did that slow his release but made him a fumbling liability in the pocket. He also
It's worth watching videos like this, and then watching Peyton, Brady, and Brees. They start into their release with the ball higher, their release is more compact, and there's no wasted motion. The ball comes out quickly (less time for DBs to break on the ball), it's only away from their body a short distance and for a short time (less time and opportunity for it to get knocked loose), and the release is high (less chance for it to get batted down, even for shorter qbs like Brees).
This is where consistent and competent coaching of qbs matters. By the time someone even bothered to correct this things with Tebow, it was too late. I also think it's indicative of what happened with Fromm. Not only did Georgia's play calling suck under Coley, I also wonder if Fromm lapsed into some bad habits that Chaney was in the process of coaching out of him.