To me I'd be happy if they kept it almost as is, but tweaked when possession is established in relation to going to the ground. In this particular case, to me possession was established when he tucked the ball as his knee was about to touch. He then twists his body and extends the ball. At that point he's established possession and made a football move, and the play should be dead as a touchdown the moment the ball crosses the plane. If the same play happened not on the goal line, I'd still like to see it called a catch once the player possesses the ball enough to be able to make a football move, even if that all occurs in the process of going to the ground like it did here. If you are controlling the ball well enough to be able to tuck, then twist and extend, to me that's a catch all day long. If the ball then pops out when it hits the ground that would be a fumble. In this particular instance the fumble part would be moot because 1) the play is already dead by virtue of breaking the plane, and 2) despite moving when he goes to the ground the ball never actually leaves his grasp.