Running Carter up the gut when BYU is inside the 5, is one of those 5 to 10 touches. And a very significant one. That lost yards, and BYU ended up with a field goal, and in a critical part of the game.
Is it really irrational to think that is a bad play call? If you're going to run that play, you run one of your power guys. IF you want or need to use Carter, you call a different play for him.
I don't hate Carter at all. I think he has a lot of tools that can be used by this offense. But a power run up the middle through a stack of defenders is not a smart call.