Old roofing regulations for texas

Was wondering if anyone knows if there are any roofing regulations on metal roofs from 5-7 years ago in Texas. I have a customer that has extensive hail damage on her roof and was denied from the insurance because of the cosmetic loss waiver. I met the adjuster and showed how much structural damage was on the roof. After this last rain the roof leaked for the first time since it was installed. The adjuster came out a second time and is now saying the roof wasn't installed correctly. He pointed out things that I know are required now but don't know if they were required then. Now they are going to bring in a structural engineer to check the roof. My questions are:

Does anyone know of any regulations that were in affect 5-7 years?

If the homeowner has been paying her insurance premium on the roof wouldn't it be covered no matter how it was installed if the leaks are due to hail damage?>>>