I had a similar situation a couple of years ago and had the same excellent service. Sent it to them on Wednesday and had it back on Monday - they explained what the correction was and the scope has been perfect ever since.
As good as Nightforce scopes are, there obviously are some errors that get out. Probably true with every manufacturer. I saw a windage turret separate completely from the body of a brand new Swaro 6x after just a few shots last summer (happened on an '06, no previous abuse to the scope either).
Glad to hear that they treated you right.
Good luck with your moose-hunting, let us know when you plink that 60 incher.