The following ARs are very interesting. If a receiver catches a pass at the 50 and is forced back to the 48 but does not down, I understand the logic of not giving him progress to the 50 unless he gets back there on his own. However, it seems like the same play over the end zone but forced back to the one yard line should be at TD even if the runner doesnt go down.
AR 5-1-3-I. Airborne A1 receives a legal forward pass one yard within the opponent’s end zone. As A1 receives the ball, he is contacted by B1 and first comes to the ground with the catch at the one-yard line, where the ball is declared dead. RULING: Touchdown (Rule 8-2-1-a).
AR 5-1-3-II. Airborne A1 receives a legal forward pass one yard within Team B’s end zone. As A1 receives the ball, he is contacted by B1 and first comes to the ground, on his feet, with the catch at the one-yard line. After he regains his balance, he runs and is downed at Team B’s five-yard line. RULING: Not a touchdown. Team A’s ball at the spot where the ball is declared dead.