because the staff knew Utah would be stealing their signs. He never talked about it publicly, but during rivalry week BYU would change up their signals and signs to try and throw Utah off because they knew they'd actively be trying to steal signs in game. Something Kyle learned more about from.......you guessed it..... Urban Meyer.
Again, there's technically nothing illegal about it.
Also, the level of success from doing that can be debated as Utah's pretty much owned the rivalry for the last 2 decades.