They're always going to throw a flag when you go for the QB's knees That being said that flag may have been worth it
Watch the replay. Dude got held around the corner and the tackle just shoves him down. What else can you do there?
they also "always throw a flag when you go at the qb's head" except today when they.....didn't so no, they don't always throw flags for that
Maybe a penalty by the books, but he was only that low because he got pushed down that low by the tackle. So not dirty IMO.