That is clearly PI on the defender. He is standing there with two arms on the receiver who then extends his right arm to get away from the D-back.
Thanks for posting this. I am now convinced that Seattle got screwed. I also like how you tried to crop the video so as not to show even more contact by the D-back and it still backfired on you.
Not to mention that he turned around, ran about 3 yards in the other direction, and caught the ball.
It seemed to me he was running his pattern, not doing anything interference-wise.
http://www.nfl.com/news/rulesdigest.html
Actions that do not constitute pass interference include but are not limited to:
(a) Incidental contact by a defender's hands, arms, or body when both players are competing for the ball, or neither player is looking for the ball. If there is any question whether contact is incidental, the ruling shall be no interference.
(b) Inadvertent tangling of feet when both players are playing the ball or neither player is playing the ball.
(c) Contact that would normally be considered pass interference, but the pass is clearly uncatchable by the involved players.
(d) Laying a hand on the receiver that does not restrict the receiver in an attempt to make a play on the ball. (e) Contact by a defender who has gained position on a receiver in an attempt to catch the ball.
Actions that constitute offensive pass interference include but are not limited to:
(a) Blocking downfield by an offensive player prior to the ball being touched.
(b) Initiating contact with a defender by shoving or pushing off thus creating a separation in an attempt to catch a pass.
(c) Driving through a defender who has established a position on the field.
The Seahawk's arm is between the Steeler's hands, as can be seen in this picture.
What cannot be seen in this picture is that the Steeler's hands are too far apart to be gripping the receiver.
Dallas fans know about blown defensive pass interference calls. Lynn Swann interfered with Benny Barnes in SB 13 yet Barnes got called. The league sent a letter of apology to bothe the Cowboys and Barnes stating that the call against Barnes was wrong. Those letters didn't have the reflective properties that a gold and diamond super bowl ring does.