The oft-cited "process rule" of the NFL rulebook has surfaced many times, most famously to deny an apparent touchdown catch by the Detroit Lions' Calvin Johnson in 2010. Here is what Rule 8, Section 1, Article 3, Item 1 reads: "If a player goes to the ground in the act of catching a pass (with or without contact by an opponent), he must maintain control of the ball throughout the process of contacting the ground, whether in the field of play or the end zone. If he loses control of the ball, and the ball touches the ground before he regains control, the pass is incomplete. If he regains control prior to the ball touching the ground, the pass is complete." 

And since he had possession the entire time, including when he was down, what you just typed doesn't apply. So...