It does not follow. The last time I went to the US, my expected stay was two weeks and I was visiting my kids. They were not false statements. Although I was showing a US passport to the border patrol agent.
In fact, when returning to Canada, I always show my Canadian passport to the gate agent. In fact, although Canada has no law against entering with a foreign passport, I got into arguments with gate agents who were convinced that a US passport plus a Canadian citizenship was not sufficient to get me into Canada and wanted to deny my boarding. Once I got to Canadian immigration, they certainly were.
I did some more digging around the interwebs and found a website that indicated the penalties may have been eliminated in 1979, the website was had an agenda but did cited a law with respect to the penalty change.
I still think a long time in secondary is on the cards
Yes - he may have annoyed Border Services at one time, but once he’s a US citizen with proper documentation for entry, no matter what he did before, they really can’t stop him from entering the USA. This is the very definition of “citizen”.