I heard one national media guy, I can't remember his name, who actually thinks that all the bad calls have to do with replay. He said the simple solution would be to do away with any challenges. He thinks that with instant replay, the refs are under too much pressure and can't perform their job very well. If anything, their would be many more bad calls without replay. Think of Asante Samuel's interception in the Denver game that was originally ruled out of bounds. Only rarely is a bad call made after instant replay (Troy Polamalu's interception being nullified).