Avocados are obviously not native, but nowadays are seen as an important cash crop and the industry is expanding rapidly. There are many farms now mainly around Chiang Mai:

20,000 baht fine, 3 year ban (assuming over 365 days). If you voluntarily leave.

If you are caught by the police or immigration, add a spell in detention.

The consequences of overstay are fully detailed on various immigration sites.

The legal situation remains as 2025.

However, Thai media is full of stories related to this (and other issues about foreigner behavior).

You can expect rigorous scrutiny on entry (not applied to every passenger), particularly if you have significant history of extensions and staying in Thailand for long periods.

This is a pretty good summary of what immigration is concerned by:

There is very little prospect of flight prices (particularly direct flights to Europe) coming down in the short-medium term.

Rising fuel prices, longer routes, (and high demand for direct flights especially), continued disruption of the fuel market, and a reduction in global refinery capacity will mean no rapid change.

A bit of anti-AI verification I assume.

Also, immigration are on high alert for suspicious individuals 😂

As John says, it sounds like that he was not being denied entry since they have left him airside but not in clink.

There is no reason he could not go to another country providing he never leaves airside (technically he is not now in Thailand).

However, this is entirely at their discretion. He needs to observe full Thai etiquette (he is asking for them to grant something to him) and request permission to leave to a third country.

I am pretty sure they have verified he has a visa application in progress- which obviously he should have waited for- and there is no reason why what they have done so far would endanger that process. At the same time, he is not in compliance, so they refused to let him pass.

I am sure they are open to the right persuasion.

No

In practice, I have no idea how it works, but apparently you can get screening and assessment at local general hospitals (in conjunction with Local Government) and then there is a pathway to rehabilitation programs. You may have already tried this, but see last slide for how in theory works:

%20Sorrasaporn%20Joowong.pdf

Penny Nave I am not American but friends have been in various countries.

Just a welfare check because the US Government requested their citizens be contacted.

No sinister reason whatsoever- I understand your general unease, but unwarranted in this case. No more than checking you are fine.