Go take a look around the NFL and you will find a lot of fine fumblers. Kurt Warner is the most notorious having fumbled 67 times in 82 career games. He has posted many multi-fumble games in his career. Brett Farve has 111 fumbles in 245 games, that's close to one every two games. And let's not forget old Ryan Leaf who fumble an amazing 24 times in just 25 games! That's fine fumbling right there.
To me, it looked like he didn't know the guy was back there until it was too late, since he was looking in the opposite direction. Thus, he was still holding onto the ball in a way that would pretty much guarantee a fumble if tackled. I blame the OL completely on that one.
Its called pocket presence, and JP is still developing that, I guess. He has got to know that vs fast d-lines like FSU,AU,UGA, theat they are always coming.
Rolling out to your non thrwoing arm side is hard. I assume thats something he is fully aware of and is working on.