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…
If I’m not mistaken, a fair catch signal specifically requires waving a hand over your head, which he never does. He crosses his arms over his chest to signify no attempt to catch ( which is only a signal to his teammates, not the kicking team. Huge call that is totally wrong in my opinion.