Back to your initial question, McGregor, I can only think of two reasons:
#1--If the Cougars don't play to their potential as a power-house-with-no-respect-chip-on-the-shoulder team (I doubt this reason).
#2--If the Cougs fight hard enough to win , but PAC-10 Stooge refs steal a close game from them (remember UA, '06; BYU must play for a margin too big for the home officials to possibly whittle down).