if he did an excellent job on the refinish, I would just accept it. I would rather touch up baseboards and have a beautiful job than to have perfect baseboards and a lousy job. It's just not a perfect world anymore and we have to accept more and more.

Actually he did a very poor job. Put 300sq ft new oak flooring over thinset without checking moisture levels. All the flooring cupped and has to be ripped up. Polyurethane has hair and dirt in it, white paint flecks from my front steps are sealed into the finish, the back half of the main floor has a satin finish on it and the front half has semi-gloss. I could go on.

Was this flooring engineered or a solid product? And, why would he place this over thinset? Need more info from you.

Stain will usually wipe clean from most paints with a suitable solvent. However, polyurethane will not.

This was solid oak flooring. It was put over thinset / in floor electrical heat which is approved for use with full thickness wood floor. He knew when the thinset had been poured and even if he did not he, as a professional, should have checked moisture levels. Apparently he did not own a moisture reader - he does now. This was not a hired handyman to install the floor - he is a professional installer and floor refinisher. Why is this relevant to whether he did a good job or not?

I could spend hours wiping the stain off but the solvent will also likely take the underlying paint as well. And what about all the white paint flecks sealed in my dark walnut floors?

Was this thinset or an approved cementitious flooring underlayment? Makes a big difference.

Your floors may settle down after any moisture reaches equilibrium, if it ever does. I say that, because there is no way to determine if you had a suitable slab for a solid wood floor in the first place. If moisture is migrating up through the slab itself and reaching the back of the solid flooring, it will never become flat. How did your installer fasten the solid to the substrate and with what adhesive?

It does sound from what you've told us that the job is unacceptable for several reasons.

It was thinset. The floors were nailed to wooden risers(?) placed 18" apart.There was no adhesive used.
When we pulled the floors up the thinset moisture was 17%. That was last week - it is now down to about 8% throughout most of the thinset. There is no concrete slab other than the inch of thinset. It's a concrete foundation wall but there is no slab. The insulation was spray foam so it's a nice closed in dry space. What is an acceptable moisture level that would suggest we are safe to reinstall new floor?

Here's another question - he seems to think we are responsible for the cost of the new wood that needs to be laid, I say no , it was his due diligence to check the moisture level and he did not. We hired him as a professional and the mistake is his.

I'm sorry, I can't comment further. Perhaps someone who has had experience with this type of floor system will give you some advice. I would be "shooting from the hip" on this one and that would not be fair to you or to your hapless installer.

I am curious to know, however, who suggested the floor system for your project. An architect perhaps or the installer? Someone else?

By floor system do you mean the infloor heat? It was purchased from a company that sells infloor heating systems..

No, I do not mean the infloor heat, but rather the entire 'system'...everything from the subfloor up to the finish on top on the new wood. Who designed and specified the way in which the entire floor construction would be done...i.e. thinset, sleepers...anything else from the subfloor on up.