The problem is you're applying an exception to the base rule. The base rule doesn't discuss going to the ground. The base rule describes what it takes to complete a catch. It includes three parts. Once those three parts are complete the process of the catch is complete, period. If those three parts are not completed then you look to the subrules below to see if there's an exception that allows for the completion of a pass without the fulfillment of the basic rules. That's where Item 1, which is your whole argument, comes in.
Your argument isn't supported by what the NFL has said about this. They said they were looking for evidence of a football move on replay and didn't see 'enough of one". If what you are saying it correct and the football move isn't relevant, why do they bother talking about it.
Follow the logic through.
Completed or Intercepted Pass.
A player who makes a catch may advance the ball. A forward
pass is complete (by the offense) or intercepted (by
the defense) if a player, who is inbounds:
(a) secures control of the ball in his hands or arms p rior to the ball touching the ground; and
(b) touches the ground in bounds with both feet or with any part of his body other than his hands
; and
(c) maintains control of the ball long enough, after (a) and (b) have been fulfilled, to enable him to
perform any act common to the game (i.e., maintaining
control long enough to pitch it, pass it, advance with it, or avoid or ward off an opponent, etc.).
So the process of catch is completed when A, B and C are finished. Now what happens when A, B, and C are not completed.
Item 1: Player Going to the Ground.
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
The problem with your argument is simple. Item 1 only applies if he is in the process of completing the catch. If Dez has performed a football move the process of the catch is complete prior to him going to the ground. You're trying to apply the rules backward. Item 1 applies only when the process of the catch isn't completed, so a football move is the only thing that does matter in this discussion. Because A and B had been done by any reasonable measure, the Refs and NFL never implied they were looking for either of those. The Refs and NFL were commenting about C.