@Phil ******
Most people who are now on long term visas had at one point spent half a year, or a full year on visa exemptions, or tourist visas before transitioning to a new status.
His case is fairly common because many people hesitate getting a long term visa, due to no actual rules governing how long you can spend in Thailand during one year on visa exemptions, setv, or metv. The fact that he was still allowed in after questioning, and the existence of border run agencies, is proof of the lack of rules.