Skip to 3:05 to see the ref announce they’re wiping the TD off the board for an invalid fair catch signal (and ensuing replay for you to make up your own mind).
IMO, DeJean was just running and not attempting to signal, and I think all the players, commentators, and fans viewed it that way live. The refs on the other hand…
I was watching this in a bar with no wound and was so confused as to what was happening. No part of me thought that he was signalling for a fair catch, and by the response of the defense I don’t think any of them thought so, either. Such a huge call at that point in the game.