"Supposedly" is the best definition I've seen for their defense. As I stated in another thread, the best offense they've faced is Boise State (ranked 83rd in scoring) and Memphis (ranked 52nd in scoring thanks to running up 63 points on a horrible Austin Peay team that gave up 63 to another FCS team and is 0-4 - otherwise they'd be averaging 19.3 points per game on offense as 16 points this year have come from Memphis' defense). No, all the offenses we've played have hardly been world beaters, but WV would have an even higher ranked offense if not for us, and they already rank 20+ spots above all of Ole Miss' opponents. Despite this, Ole Miss is surrendering less than 2 yards less than us per game.
Anyway, my point is that Ole Miss has feasted on truly sub-par offenses, while we've played at least one offense light years above anything they've faced (West Virginia) and only gave up 16 to their offense.