a) secures control of the ball in his hands or arms prior 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.).
If all that were needed were a certain amount of time, there would have been no reason to go into
examples of football moves. It was worded this way so that they wouldn't have to make a separate rule for end zone catches -- where no football move would follow (a) and (b), and so the official is forced to use his/her judgment to determine whether enough time has passed. Obviously, since any player who is short of the goal line will try to advance the ball, officials know they can look for the football move as an observable standard in the field of play.
Since the Dez play happened in the field of play (outside the end zone) they were ostensibly looking for a football move to complete the catch process. That's why Blandino said Dez needed to
"extend his arm or reach with two hands," instead of simply saying he needed to hold the ball longer.