being possibly the last play of the game for a team as far as their ability to win, then it is right that it should be called. It SHOULD be called every time it is used. That notion definitely hasn't been followed and I'm not naïve enough to say BYU DB's never use the tactic, but it always seemed to me that Utah took it to another level.
The Utah DB was either tired or lazy because in this case it was ever so blatantly obvious. Further, because the call was made before the sack, that indicates that it was not an attempt by any ref to specifically influence the game's outcome, but force Utah to play by the rules to win the game.
I still remember Michigan's Bo Schembeckler, after his loss to BYU in the 1984 Holiday Bowl, claiming that BYU was the "holdingest" team in America. I can't answer to that specifically and whether it was sour grapes, but for as long as I have watched the U play defense, that has been their standard to attempt to cheat to get away as much as possible with holds on receivers. It very well could be that I'm hyper-focused on watching for it when watching a U defense, but it's not like they do well at hiding it. You can't cry about it EVER if you did it and got caught in that one instance.