I can see that being a compnay director in this situation would be a good way of hiding a persons income and I am sure they will wake up to this loop holes soon. Similarly an offshore trust could be used to hide wealth.
I would like to throw another spanner in the works. Could it be claimed by the tax office BOI and immigration that a person who comes to Thailand and is working for a foreign company, has that person established a branch office of that foreign company?