[Adam]

I'm going to advocate a sort of compromise position that depends upon the trajectory of the shooter. If the shooter has the ability, demonstrated by the trajectory of his jump, to jump over the defender, and the defender then moves backwards into the landing zone; I'd say it's a blocking foul based on scrapper's logic.

If, however, the shooter's trajectory would take him into the defender and the defender simply moves backwards, maintaining LGP, PC (or incidental).