NFL will look at the fumble-out-of-end-zone rule

lol. That is assuming the refs apply the rules the same to all teams. They would claim the tip of the ball actually broke the plane even though he dropped it almost a full yard before the line even after seeing multiple replay angles. Or they would just say it wasn't conclusive evidence.
Colston was also known to throw the ball down as soon as he broke the plain. There were a few times I thought he did it a bit to early. If I was a coach that had a player that liked to do that I would let him know that if he ever gets called for it it and it is ruled a fumble, then he will be benched for the rest of the game and receive a team fine for conduct detrimental.