If you want to get technical, this topic is better dealt with by others since it is a quality matter rather than dimensional metrology where I hide out. But, disputes go on every day over measurements and sometimes resolving them can be quite challenging—when possible. Yes, there are protocols in this area but when the shouting stops it always comes down to basic metrology so that’s my excuse for wading into treacherous waters.
I would be remiss if I didn’t offer some advice to avoid such disputes in the first place. The easiest way is to determine how your customer will check what you’re supplying before you switch on the machines. If they have better toys than you, you’ll have to upgrade. If they have worse or don’t know what they’re doing, you could get technical and point this out to them to avoid future battles. If they don’t like to hear this, you have to revert to politics. This means get them to agree with you using the same methods and hardware they are using and ignore the metrology involved. The product measurements may not be worth squat, but at least you won’t be fighting over it. And if they discover this, you’ll have their agreement on method to cover your end. Not the way things should be, but remember it’s politics so you know how that system works.