Jan 7th 2019, 0:01:10
Apparently it's an actual rule:
"When a pass is ruled incomplete, either team can challenge that it was a catch and fumble and that they gained possession of the ball, if there is a clear recovery. The replay official can also initiate a review of this play if it occurs after the two-minute warning or during overtime. If there is video evidence of a clear recovery by either team, the ball will be awarded to that team at the spot of the recovery, but no advance will be allowed. On fourth down or inside two minutes, the ball will be brought back to the spot of the fumble if recovered beyond it."
The key sentence then follows: "If there is no video evidence of a clear recovery or the ball going out of bounds, the ruling of incomplete stands."