"A player shall not: hold, push, charge, trip; nor impede the progress of an opponent by extending an arm, shoulder, hip or knee, or by bending the body into other than a normal position; nor use any rough tactics."
It seems to me the player on all fours is bending his body into "other than a normal position." If this impedes the progress of the defender, then I've got a personal foul. Any contact whatsoever is going to get called by me on this. If there's no contact, I'll wait til he starts barking to call the T.
