Yeah--someone with his high level of success this year--to find certain things he messes up 80% of the time---that has to be a small sample, no?
If you listen to the pod (you should it was a good episode), he goes through a bunch of the QBs, but basically what he was talking about was going through every play, and then pulling out the plays that have real value in predicting NFL success, so you're eliminating a bunch of play types, a bunch of situations etc. So on the key types of plays, he was seeing a lot of issues. In particular he talked about how poorly he handled moderate pressure, so what is a good pocket in the NFL but a bit sloppy by "Alabama with 5 future pros on the O-Line against scrubs" standards, like having to slide up, or move away from guys who have been blocked to the ground, etc.
I obviously haven't seen all his snaps, but other people who are dubious about Jones note a lot of the same things... he didn't have many tight window throws, and the ones he had he wasn't anywhere near as good on, he doesn't manipulate the pocket well, it's either an enormous immaculate pocket or he leaves it, etc.
He also did note that his first thoughts on Jones were more negative, then he saw he could make some throws, but felt he wasn't a high 1st pick at all.
The thing that makes Jones hard to project is... he had a lot of success, but he also was in a position where any even backup quality pro prospect should succeed... he ran more RPO and PA than any of the other QBs, he had by far the best O-line, the best skill position players, he had a lot of simple throws to wide open players... and that isn't going to happen in the NFL no matter where you go. You have to handle at least moderate pressure almost every snap, and most of your throws downfield are going to be tighter windows, guys don't get WIDE open as often in the NFL.