The head of officiating lied. This has been gone over thoroughly. The evidence is there of how they ruled that play similarly (same season and WR in one example). Going to the ground "during the process" = contacting the ground before the requirements of a catch are complete. It doesn't supersede anything. It's a rule for when there isn't a chance for the typical requirements to apply (sideline/endzone catches, player on the ground unable to advance).