But the rule says ATTEMPTING to catch a pass, so clearly he was.
Article 7: Players in a Defenseless Posture. It is a foul if a player initiates unnecessary contact against a player who is in a defenseless posture.
(a) Players in a defenseless posture are:
(1) A player in the act of or just after throwing a pass;
(2) A receiver attempting to catch a pass; or who has completed a catch and has not had time to protect himself or has not clearly become a runner. If the receiver/runner is capable of avoiding or warding off the impending contact of an opponent, he is no longer a defenseless player;
(3) A runner already in the grasp of a tackler and whose forward progress has been stopped;
(4) A kickoff or punt returner attempting to field a kick in the air;
(5) A player on the ground;
(6) A kicker/punter during the kick or during the return (Also see Article 6(g) for additional restrictions against a kicker/punter);
(7) A quarterback at any time after a change of possession (Also see Article 8(f) for additional restrictions against a quarterback after a change of possession);
(8) A player who receives a ―blindside block when the offensive blocker is moving toward or parallel to his own end line and approaches the opponent from behind or from the side, and
(9) A player who is protected from an illegal crackback block (see Article 2);
(10) The offensive player who attempts a snap during a Field Goal attempt or a Try Kick.