I think you will find it depends what part of Thailand you are in and what the local officials say or how they interpret the law. A Canadian friend died here, police informed, body taken to the morgue. I informed his children in Canada about his death, they flew over. The police informed the Embassy, no papers were required from the embassy to cremate the body, did not have to wait for any paperwork to sell his bikes and belongings, BKK Bank allowed them to take the money out of his bank account via the ATM (left a few Bhat in there). I sent his passport back to the embassy and they cancelled it. I am sure what you have said is correct but if you live here you will know local officials have their own way of doing things, some by the book or some with the least amount of work.