There was an aluminum extrusion company that falsified test records for years. They got away with it because what's a few % when your customer's safety factor is 2. Once they got into weight sensitive aerospace applications, where sometimes the factor is 1.2, rockets starting blowing up on the launch pad.
It did result in jail time. The linked document states that the testing lab supervisor was sentenced to 3 years. (Not sure how much of that time was actually served, apparently he was suffering from dementia.) More info: https://www.oregonlive.com/portland/2018/08/company_supervis...
https://www.justice.gov/archives/opa/pr/aluminum-extrusion-m...