The reason he is so wide open is that Kupp was catching everything in the first half of that game. On that play Kupp and Everett are running up the middle, Kupp curls back and Everett keeps going. As Kupp already had a TD and 3 or 4 other catches by that point in the game, both the LB and CB move to cover him and leave Everett uncovered down the seam. If the throw goes his way, it is at least first and goal if not a TD.
