Here, watch the video again. Especially right around the 44-45 second mark when they slow it down. Suh's hand (just 1) is inside Delhomme's helmet, and turns his head almost 180 degrees. And yes, if the play were over (like say the RB had fumbled the ball out of bounds) and Suh slammed him to the ground for no reason, I'd probably call it a dirty play. But regardless, if you watch the video like I said, it's clearly a facemask. That much is clear at least:
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