That may or may not be. But he was on his way down and the rule is clear that if he is falling to the ground he must maintain control when he gets there.
If the receiver falls after the catch, he must hold on to the ball after hitting the ground or it is an incompletion
Well, that depends on what transpires after he catches the ball. How long after the catch does that apply? At some point, does the receiver not become a runner?
Watching the slo mo of the catch on this page shows me that it was not a reception and also not a reception followed by a run after all.
Refs got it right IMO.