This was the "struck down on the road to Damascus" moment for me as well. After watching him in that game, I was of the opinion that you can't keep this type talent on the sidelines long. You have to find a way to play him. I'm certain if asked, Gary Danielson would point to the Vandy game as well. Especially seeing how he basically had to go clean himself after the game from fawning all over Tua. I'll never forget when he turned loose of that ball where he was spun around and hit the receiver in the back of the endzone. Danielson's "standing in awe" reaction. Unreal.
We have 2 years worth of evidence that Jalen wins the easy games and doesn't perform well against teams that can neutralize his running skills. When those teams force us to pass we don't make first downs, don't score as many points and we struggle to win (go watch the Washington and Clemson games in 2016).
I'm not basing my assumption that Tua starts on his second half performance against Georgia alone (although if that's all we had to gone on, it's good enough). I've thought Tua was a better passer (throwing ability alone) since the first pass we saw him throw last year during his A-day performance (remember how Kirk Herbstreit was drooling over him???). Of course, we also saw how our first team neutralized him in the second half of that game and so we knew he wasn't ready right then. But last fall, over the course of the year, we saw him growing and doing the other things great QB's do. After I saw "the play" against Vandy, I knew he had something Jalen didn't (and most other qbs don't). And then when he outplayed Jalen against UT (although he had the one, freak INT that got returned), I was convinced he had pretty much passed Jalen all around.
And then Georgia happened and the whole world now knows.