I know that from the days of Watergate... the notion of two sources on a story has become the popular dogma about how you confirm something. And there is a lot of truth to that, but there are all kinds of ways to check to the extent that you can, a story that you get.
It could be argued that, in Thailand, many foreigners have come and gone, and the number of people who are considered to be Thai have traveled abroad in a great number.