I remember the BYU portion of the crowd erupting after they showed a Kehl INT that the officials had waved off that looked like a legit pick. The UCLA fans sitting near me were pissed off that they were going to lose the ball. Not long after, the refs let the call stand and the stadium erupted in boos. After that, they didn't show any more controversial plays on the replay screen, including a fumble called against So'oto (still as a TE at that time) which was highly questionable.
As for the BYU replay board, I don't have any complaints about it. I get to as many road games as home these days, and don't see much difference between BYU and other schools I've attended, when it comes to the replay board.