You are being pedantic. Normally I would agree that anyone quoting visa on arrival you should correct them and tell them a visa on arrival is 15 days. In this case the OP clearly stated he was from the UK and alhough technically incorrect in saying visa on arrival, we know what he means. This however does yet again raise the importance of getting the terminology correct. Visa exempt entry 30 days, visa on arrival from about 19 countries 15 days.