This goes back to stuff I have talked about in the past. I have heard that in the past at least the government did occasional random sampling of motor oils and bench tested the oils to see if they contained adequate chemical additive content, that the oils were of the correct labeled viscosity, etc.
There were motor oils failing to meet the requirements in this testing. Which just goes to show that the API and the SAE do not appear to really offer much protection to the public when it comes to motor oil quality. If poor quality motor oil that can damage engines is really being sold to the public, and if nothing is done about it, that is a scandal.