So I went and watched the entire video this is cut from here https://www.youtube.com/watch?v=E5JTn7GS4oA

He states later that the claim in the title is a story they tell to get you to focus on money as debt, just as the story of medium of exchange being a commodity to eliminate coincidence of wants is a story. It doesnt matter if it's true being his point, the story is to convince you of the theory by directing your attention so that you view money a certain way.