The bore size of a stock wheel is 67.1mm and I've always seen hub centric rings designed for Mitsi's labelled as 67.1mm and sometimes 67mm (potentially rounded down), but never 67.0mm.
The work being done is boring out Nissan wheels, as such I'm sure 67.1mm is going to be the size you want him to bore out to.
Well he bored them at 73mm so they would fit on anything in the future I guess this will be good for re-sale. Not sure if I should be pissed or impressed. I need to get some center locators now...
I'd be pissed!!! He should have made them what you asked for, 67.1!
You now have to get them to install locator rings which work OK, but a properly sized hub would have been better. He should have done what you asked.