Australia recognises countries that have good driver training and similar standards in order to obtain a license and rewards citizens of those countries with an automatic Australian license on application and payment of the license fee provided their license is in English or they have an English translation.

Being a Thai even if he held a full and valid Thai license he would have to sit the tests to obtain his probationary or full license as Thailand is not a country that Australia considers, quite correctly, to have equivalent or sufficient driver education and training.

That probably explains why he was still driving around on a Learner's permit.