SGS is trying to comply with ISO 17025. That standard requires that for a laboratory to become accedited, they have to have a quality managment system that addresses the competence of staff and the methods and calibration of equipment. If any of these are found to have failed, the must investigate and take corrective action or risk losing their accreditation. It is less about lawsuits than about having accurate and repeatable tests.

It is normal practice to have samples of known chemistry (not quite placebos) to check the accuracy and precision of the test. Noront would probably be made aware of these results by their QA consultant, but told to disregard them because they didn't pass muster.

The information supplied to me by a VP of Quality for a forturn 500 company.