[grizwald]

Agree with some on here that it doesn't matter based on the momentum of the receiver being the same direction as the push from the defender. They look like they are both leaping in the same direction to me. It doesn't appear that the defender pushs a different direction from his own momentum.

But I saw it live, replays on the jumbotron, and on here - I'm with Big John as far as what happens without the contact. I think without the contact he comes down in bounds.

The defender didn't push him really hard, but it totally knocked him off balance and his legs move suddenly to try and find the ground. Good NFL and college receivers learn to ignore the unnatural feeling of losing your balance and dot those feet/foot in bounds anyway and just pay the price by eating the turf sometimes - but this receiver doesn't have that kind of experience to do that.