D800 is within factory standard! Needs +20 to stop it front focusing.

Good point. Try it with all of your lenses. If one or more cannot be focused to infinity you would have a reason to claim it is defective. Then you could send it back with the lenses and ask them to calibrate it so it will focus both at close distances an at infinity. If they can't, then you could demand a new body.

That sounds like a good idea, and maybe why they see it as in spec. Since they didn't have your lenses to test with they may have just been calibrating the default setting. Once you have determined a good default setting you can test to see how much variation there is in your lenses.

--
Robin Casady
http://www.robincasady.com/Photo/index.html
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."
— Bertrand Russell