I the official got hoodwinked on that one.
Yes, the offensive player had his hand in contact with the defender but I don't see anywhere near enough force to cause the reaction that followed. The defender jumped away from the contact creating the appearance of a foul.
The view from behind makes it most apparent. It shows that the offensive player's arm really wasn't even in the back of the defender at all but maybe to on his side. A push form that point wouldn't have caused the movement seen from the defender.
