All of this speculation about " how could they afford to buy this large property" is off topic bs!
I live near Kanchanaburi and 4 years ago bought 50 Rai (correction, my Wife bought , lol) of land on a sealed road , with water and electricity connected for about 2 million baht. His land, on the newscast, looks unimproved - so I doubt whether it would have been a huge expense more than 10 years ago.
'Most of the listed species in the original article - even the exotics - do not require a permit to own. It is only the civet and reticulated python, Thai species, that require a permit. The Sulcata Tortoise, though on the CITES list, is readily available in Thailand, and permits are easily obtained.
While in the area, these officials should visit the Surasi Camp Zoo in the Kanchanaburi district. This zoo has many local species, such as Civets, Binturongs, Bears, and many monkeys - being kept in deplorable conditions.