I think the NFL should be reviewing all 'big penalties' such as personal fouls, etc and fine the referee's based on there performance much like they do with players. If a ref makes a terrible call such as the Graham penalty then they should be fined just as a player would be should they commit a head to head contact. This way the refs would need to be certain it was in fact a PF and eliminate some of the questionable calls unless they were certain of it. It's too big of a penalty to call without being positive of it.