This is one of my pet hates, Kurtz, when authors can't be bothered to research the places they write about. I suppose he thought setting his book in Thailand would be exotic and quite different. I've found authors (unfortunately American ones - sorry ) who write about things in England that seem to come out of a fairy tale. Chris Kuznetski is one - he makes up a lot of stuff about UK because he can't be bothered to research properly .... and then he makes a fortune from his awful books.
I'm amazed that the main character in the book you mention can speak fluent Thai - clever man. It took me ages to learn to speak the language and I still can't read it. I still get the tones wrong sometimes