Yep. I think your assessment is spot on. Any pressure containing equipment has very high standards of construction, which would include inspection to all relevant codes by qualified inspectors. I think the best case scenario is stated in the letter from BP at the beginning of the Inspection Trends article - a case where the false credential was caught before actually putting a unit in service. A tremendous amount of high pressure work to redo the documentation and spot any problems. Worst case is as you say, something fails catastrophically and there is loss of life involved. In that case, the viability of the company is at extreme risk and if it were shown they took part in the fraud, their odds of staying in business are not much better than zero. The inspector himself? Well you can't get blood from a turnip so a lot of companies wouldn't bother, but I have seen a case where the customer did just for punitive reasons. And the claim there was negligence, not fraud, the inspector was properly credentialed.
Let me add my thanks to the others here. I welded for approximately 30 years before recently moving to the inspection side of the business, and I do appreciate your efforts. They benefit every holder of the CWI credential. In my area, Houston, a CWI is probably the most respected of any of the NDE credentialing and its people like you and the other guys here that make it so through a lot of hard work and dedication to the profession.