Al Groh held a #5 Clemson averaging 40 points a game to 17 once, too.
I'm not one of the detractors of the guy, I'm just in here to point out it's silly to use a single data point as evidence in either direction. I'm sure we could find another game where a team with a less-than-stellar offense shredded him in some other arena one time. It's excellent to think we have a guy who can get our defense ready for one big important game with a lot of prep time, but we're never going to get to that stage without a consistent defensive effort week in and week out. When attempting to decide whether that's what we're getting, the Auburn NCG is an outlier.
This is one reason I don't like using the argument that he helped coach Auburn to a championship to support the notion that he's a good hire, which he may or may not be independent of those facts. That Auburn defense was nothing special. They got done what was necessary, but they had Cam Newton giving them a lot of room to work with, and he was singularly credited for their season at the time and even still. In many media outlets it was characterized as a championship trip in spite of their porous defense. Based on the season performance, most were billing the upcoming title game as an epic title shootout and there were articles TTE of "Defense Wins Championships? Think Again!" all over the place.
I'm not a fan of rewriting history to support a point. Let's call it what it was and move along, there are much better supporting arguments for the guy than his Auburn defense, especially considering how it collapsed later. We'll credit Roof for the good in the same breath as we blame Chizik for the bad, but they were both there the whole time. It's just not a strong point, IMO.