there was some jackass in the southwest corner of the stadium blowing a whistle all night in a pretty obvious attempt to disrupt the game. The odd part was there didn't seem to be any rhyme or reason to it--it happened both when ND and USC had the ball.
It was odd that they did replay that one down considering that it happened all game. In fact, in an earlier play in the series, you can see that Okwara stops his pass rush because he thinks the officials blew a a whistle.