To me, admittedly a non-expert, it looks like his thumb is exiting the ball late. It's almost as if it's coming out almost in sync with his fingers. He's tracking almost like a spinner, and he's very near the top of the ball, but he's not getting the length that spinners get. In the second video, it looks like his thumb may not be all the way in the ball.
Basically, I'm saying that he probably needs to work on his release and definitely get an accurate PAP measurement before any real suggestions can be made.