Most likely true in this computer age ...if he was flagged. But why return to passport country ... he could simply go to Laos and practice Laotian Muay Thai or Malaysia. etc ?!
On the one hand Thailand promotes tourism ... a 6 to 9 mo visa would follow. Whether I'm "living" or a "toyrist" I'm still contributing daily to their economy. But I also am mindfully we are all just guests in their country.
I've even over stayed my extension 2 different times. They weren't happy but nothing about not allowing me back in (just pay fine). Knock on wood most agents very nice at land crossings especially compared w attitude you get from usa customers agents.
I'm on a tourist visa ... used 30 day extensions for 11 months . I've never had a problem other than only allowed 2 land crossings per year then mustvfly back in.
visa exempt I've never heard that term before after nearly 1 year dealing w Thai immigration. If it walks like a duck and quack like a duck ...it's a Duck ! All semantics