You're exactly right, it's almost the same as the difference for the entire ACC season.
Team Oeff Deff Margin
Duke 1.09 0.90 +0.19
UNC 1.04 0.93 +0.11
As a further point, this would project Duke to win 68-67 (in 69 possessions) this Saturday at Chapel Hill. Compare that to Pomeroy projecting Duke to win 75-74 (higher pace game).