[elblanco]

>No, strictly speaking they were reading Chinese text in Chinese.

That's only partially correct though. Often as not, before Hangul was introduced in Korea, or Latin alphabets were modified for Vietnam, many people wrote their venacular using Chinese logograms, with the meaning known, but the word order and pronunciation adapted for their own language. Korean in particular has a whole class of special characters to capture the particulars of Korean grammar and language when written with Chinese characters. http://en.wikipedia.org/wiki/Hanja

Most Koreans will likewise pronounce Hanja using Korean words not Chinese ones. Like 'Dae' (대) for 大, 'In' (인) or 'Salam' (사람) for 人, 'Sal' (쌀) or 'Bap' (밥) for 稻.

You are right that, in the old days, because of the nature of the political ties betweem 韓國 and 中國, it was expected that formal government documents were written, read and pronounced in Chinese. But in general, most Koreans today do not know how to read Chinese out loud in a way that a Chinese speaker would understand. Most of the time Hanja is just used to clarify homophones from Koreanized loan words from Chinese.