My wife is a Thai university Asociate Prof, PhD (not a Thai PhD) and would run rings around all fly-in, fly-out pretend farang (so called) teachers' who supposedly know how to teach English grammar.
Seems these people don't want to be Thai but are more than happy to be connected with the Thai electricity grid, water, roads, health etc., typical attitude - us us us.
Debatable that he had / has the intelligence to orangise a coup, he probably run it etc at the behest of others - now who that is is probably not open for discussion.
Not sure about it not being illegal - it was the practice by many but probably not tracked by ATO as there wasn't any communication between ATO and Centrelink - however this could very well change if the current proposal is adopted.