In high school for sure, and probably in college also, there are just not enough good officials to go around. They're lucky to get enough warm bodies in stripped shirts on the field at game time.
In college I'm not sure if they put the best, or the worst, on replay review duty.
I have no dog in the GA-Tenn fight (pun intended), but I thought sure it was a safety. If they had ruled Hooker threw an incomplete pass, it looked to me like it would have been intentional grounding, and I have no idea what the penalty would be for grounding in the end zone.