I’ve watched it many time, he was VOLUNTARILY running to the back of the endzone, which took him out of the play. The trailing guy barely touched him and he never got redirected.
The trailing guy pushed Gronkowski as he slowed and turned, but did not redirect him, but was important because he was behind the TE and blocked out until Kueley completely redirected Gronkowski, wrapped his arms around him, and drove him backwards from a point about 2’ from the catch point to a point about 5-6 yards away along a completely different vector.