For a guy that big and strong, it has to be the shoulder surgeries. Did you notice his throwing motion looks different too? Much shorter, quicker release back then. Mobile QBs have a short shelf life unfortunately. They are exciting to watch.
I'd guess that the defending would have been a lot more aggressive it the play actually happened in the endzone. Given how far outside it happened I don't think the primary worry was allowing a catch.
If we had one more timeout it would have been used on the Texans possession to keep the game clock around 50-ish seconds. But alas we had to use it when Wynn got his knee shredded. There isn't scenario where we end up with a timeout on that final hail mary possession.