There are lots of other ways to determine what things are like in North Korea besides paid testimony from defectors. In fact, the interview in question mentione

There are lots of other ways to determine what things are like in North Korea besides paid testimony from defectors. In fact, the interview in question mentioned at least one, namely books published by the government. The post author avoided mentioning any other means, and has not explicitly stated a belief that an authoritarian country can't be just as good as a liberal democracy. I am going to assume that is what he believes until he states otherwise. Oh, and as long as we are at it, what is your belief on this matter?