"he is an engineer at heart and speaks up when he sees people make what he believes to be engineering mistakes. He has written letters to state and county governments and testified before a county commission. But Wayne’s troubles began when he when he agreed to help his son, Kyle, a North Carolina attorney, with a case about a piping system that allegedly flooded a few local homes"
If he were telling lies, he would be legally accountable to the individuals or companies that his lies harmed. That would probably be an easy case to bring against him to stop him from telling lies. But this approach of trying to silence him on grounds of not technically being an engineer shows plainly that he is telling enough truth that he wouldn't be accountable for lying and causing harm.
Cases like this are probably common, although the methods of silencing vary from situation to situation. While the US may not be as corrupt as many other countries, it still has a significant amount which ultimately harms the general public and certainly harms the few individuals that find themselves on the wrong side of a corrupt authority.