It may not have been obvious to 90% of the people watching the Superbowl that the refs got more "involved" once it began to look like the 49ers might walk away with it. But as a Saints fan, I've seen behind the curtain and I know that Oz is a big fat pasty bald-headed liar. So I saw it happening. Actually expected it to happen sooner.
My wife asked me why the 49ers weren't trying to score in that last minute drive before halftime. I told her that it could be Shanahan attempting to keep the score reasonable as long as possible so that the refs didn't get that call from New York until closer to the end of the game where anything could happen. Wild theory, but it fits. :)