No, it was not a "facemask" penalty, it was incidental contact from a player being flagrantly interfered with, as a direct result of that flagrant interference; IIRC, the defender stuck his head into PRich's helmet, which could have been called a penalty as well, for helmet-to-helmet hit on a defenseless receiver. The refs were correct to NOT bail out Detroit with a call on PRich's non-penalty-level incidental contact.
It was just NBC drama queens stirring up schkipperke, which is their job, to get fans emotional engaged. No doubt Collinsworth and Co. were given some storylines to hammer on.
It's actually a good thing for the Seahawks to be given the villain part in the storyline. The NFL needs a villain. And what better villain to cast than the Seahawks against "America's Team", the Cowboys.
I do believe the league "influences" games, in assorted ways. It's an entertainment product.
If Seattle is being cast as the villain, the NFL is less likely to "influence" the Atlanta game towards Atlanta, thinking that a game of villains vs. choir boys is a great story line for the NFC championship and TV ratings and Internet click-bait.