Question for anyone with experience with this:

I recently had a 1/2" engineered floor installed (hickory with medium stain). When the installers were finished they proceeded to wipe the entire floor down with paint thinner. This wasn't meant to wipe up any glue since there was hardly any that came through the seams. The installer was simply going over the entire floor to clean up the dust and footprints but was using the rag that had been dipped in thinner. It wasn't soaked, but there was still plenty on there. Now my floor has that "dull haze" that I've read about in various posts and articles on the net. It kind of stinks because you can see the shoeprints from his sneakers as he walked over the spots he was cleaning (probably because his shoes wiped away the thinner from those spots). So here's what I'd like to know:

Is my finish permanently damaged? Will that haze ever come out? Is there any solution for this problem?

Thanks for the feedback.

Clean the floor with Bona Hardwood Floor Cleaner. That should remove the haze.

Its extremely unlikely any damage occured.
Its best to use a two part remover/cleaner to remove excess adhesive. The first part removes the glue, the second part removes the remover, so to speak; which is causing the haze.
Since the mineral spirits has already been used, ya; like Gary says Bona cleaner should look after that haze.

Thank you both for the replies. I'll give the Bona hardwood cleaner a shot.

To answer your question....

Paint thinner = 100% mineral spirits.

100% mineral spirits is a safe way to clean polyurethane. Your floor is not damaged and will not be damaged.

If you look in any manufacturers installation instructions for glue down hardwood, it will recommend using mineral spirits for clean up.