is no good evidence for it. Sure, it would make BYU look better if USC can beat a top 10 team...but even better, it lets us pretend that Utah didn't just beat us a few weeks ago for the 9th tiem in a row. We are better than Utah! We beat USC!
More likely, USC is about as good as they showed vs BYU. This indicates that BYU is pretty good, and USC is also merely pretty good.