The walls will be to have a remediation. In Texas it has to be filed with the state and done by a licensed mold remediator. Once the rock is removed, then you can do an assessment. The studs will have to be treated. The restaurant is at a high risk right now. I do not recall the sq ft. of mold required to be removed, but I would have it done before there are respitory problems or lawsuits.

There could be roofing problems as well. It is not accepted practice to hand wall vinyl on exterior walls,

Is this in a city or rural. Rural does not have in the most part inspection programs by the county. You could obtain the construction docs as well.