There are too many such people around. Just bring your visa and entry proof i.e. money hotel return flight and let the supervisor handle things if meet with batty I.Os
She might be the same nutcase I met. Plumpy lady that kept shouting at me I'm on too many visa exempt. The supervisor let me through though in the end.
Maybe not at CW but likely accepted at outbound immigration counters. Almost every trip out of Thailand will see at least one person losing their TM6. The IO just gave them a new one to fill it in.