I didn't hear him say they're the best defense. Right now, the comparison is there, but it shouldn't be. We're much more efficient defensively, and our style of defense is very different. The points allowed is back and forth with us, but take into account their incredibly slow pace (next to last in the country), it's significantly easier to slow a team down. That said, Virginia is not an athletic team, they're not a very deep team, they don't want to run with teams like Kentucky, and I think they could possibly struggle with Louisville in that regard, even if Louisville is incredibly inept at shooting the basketball. UVA don't force many turnovers, and they really have no individual show-stoppers on the defensive end.
That said though, UK vs UVA in the title game is very possible, but I don't see Virginia giving UK a ton of problems overall.
Just my honest opinion.