Because he didn't actually grab the facemask. He hits it on the way to grabbing his shoulder. The rule is you have to grab it and then either hold on or twist. That didn't happen. Several years ago, even incidental contact with the facemask was a penalty. That isn't true in the NFL anymore. I'm not surprised they made the call because it looks like a face mask in live speed action. It's an understandable call to be missed but it was missed. Unbelievable that they can't go to the replay for penalties like that. I understand not allowing regular holding calls to get reviewed, but a call like that, which isn't a judgement call at all, should be eligible for review. Also, I liked the old incidental facemask 5 yard penalty. The distinction is key IMO, but whatever. Even if they did review that, I'm not really sure that would've been reversed. In real speed, that absolutely 100% looked like a face mask. On the replay, it still looks like the defender got a finger on the face mask, although obviously it wasn't anywhere close to what appeared to happen in live speed. As long as there's any contact to the head area of a QB, based on the NFL's rules, that's a penalty. They do need to make PI/face mask/unnecessary roughness penalties reviewable though.