Aided by two missed tackles. BYU makes those two tackles and he likely doesn’t go for over 100 yards.
So, I don’t think he destroyed the defense.
His other two TDs came from missed tackles as well.
He hurdled satuala (amazing play by Gordon) and wall basically bounced off him as he strolled into the end zone.
Satuala doesn’t go so low and pushes him out, maybe he doesn’t get the TD there. Same thing with Wall. Who knows, maybe they just pound it with him and he scored those two TDs anyways.
But because of the missed tackles I’d say it’s hard to say he destroyed the defense. To me, it was the QB runs that were the big killer for the D.