Really? I'll concede you Death Valley isn't easy... but they've played nobody outside of Tennesse who's probably one of the most up and down teams in America.
Their defense is elite yes, but they've struggled in the passing game this season and LSU has (for the most part) shut them down.
Keep in mind LSU has played pretty poor as well. The chompers might be #1, but their certainly very, very vunerable.