There's so much talk about whether the hold should have been called "in that situation." For example, Pat Forde says, "I didn't like the call. You can throw the flag, but in that situation I didn't like it." At about 1:33 of this video
https://sports.yahoo.com/byu-remains-perfect-wild-win-201646785.html
My opinion, which I don't think should be controversial but apparently it is, is that the referees exist to enforce the rules. I don't see anything in the rulebook that says certain penalties don't apply down the stretch of a close game. Nor have I seen anything that says referees should give greater discretion to players on holding penalties (or anything else) if the game is close in the 4th quarter. I haven't read the entire college football rulebook, but there's no way there's anything in there.
If college football wants no whistles in the last 2 minutes of a close game, it should make that clear. It should make a formal announcement, "Starting this season, referees are only going to call egregious penalties down the stretch if the game is close, other than that you can get away with it." Then in each game where the "new rules" apply, to make it fair the referees should notify both teams and there should be an announcement made so all the fans know. "Because this game is close and there are only 2 minutes left, we are now moving to the new rules. The referees will only call egregious penalties from here on out." That is the only way to be fair to both teams. And the fans know so we can adjust expectations accordingly.
Obviously this will never happen because the whole idea that the rules of football should change in a close game is absurd and ridiculous.
The rules are the rules. They should be enforced even-handedly from start to finish no matter the score or time left on the clock.