@Ar ******
your friend is using visa exempt, while for his purpose of stay he just need the correct visa, mist likely METV. So he is just using the visa system incorrect, accidentally because he does not know, or on purpose because he wants to save money. You cannot blame immigration officers for this, and I certainly do not wear a rose colored spectacle. I was once stopped at the border after shopping in Malaysia, completely without reason, so I know they are not always acting according the rules, but your friend just has to get the right visa if he does not want to have risks. And parking in Hat Yai is never easy, I think the officers working there just use up all parking space.