I'm very confused now due to I spoke with a hardwood manufacturer (BRUCE) and they (technicans) told me this was an approved installation and was even listed in their installation manuals! I trust that the information provided by you is correct therefore I have full intensions to contact the contractor and recommend that he start ripping the floor up. (this happens to be an insurance claim anyway)! Sounds like you are very experienced in what you do.
Thank you again for the valuable information provided.
Shellie