I feel so sorry for all these people being force to buy a return ticket by whichever airline that imposed "Law" just for there own justification, & bla bla bla.
As far as those airlines I have booked and flied, they warned upfront to have the proper documentation, but I was never ever denial at boarding nor custom by any Thai officers. I was always respectful at the custom, and tell them I am not sure how long I will be there and I am planning to take a bus/train out of the country. Stamped 30 or 60 days of visa, done!
Most people do just fine, even with the evil airlines. There is no requirement to purchase a "return ticket" from the airline, only documentation to justify one's entry status.
If "Swept Away" is carrying a Chinese passport, he will be entering under the "Visa on arrival" scheme. That is different then someone visiting from countries like the US or Malaysia, who are granted entry "without visa". These folks hit a different screener at immigration.
In any case, the rules are in place. One can choose to follow them, or ignore them.
Thailand's habit of enforcing rules, by whim, is a two edged sword. For the most part, it allows people the ease of bypassing regulations, often for a small fee. But, when someone decides to enforce the rules, it can be even more expensive and inconvenient.
The bad thing is that the enforcement status, and even the rules themselves, can and often does change without notice.
Rules are rules. Experience is anecdotal. I believe one should make an informed decision.
Everyone's mileage will vary.