Look, he's an Economics prof. They get things wrong, because THEY THINK (about some pretty profound subjects)!
I have a degree in economics, and having seen the way both the American and European economic situations have evolved over the past 30 years, aside from the basics that one learns in Year 1, there is still very little that we understand about the science. (Yes, economics is a SCIENCE!)
It aint easy to take any economic situation and, with time, not wonder about certain aspects that make for some very curious turn of economic-events. And, since economists do this more often than the ordinary-dorks on this forum, they get it publicly wrong. Or a bit wrong - especially if they are teachers of the subject-matter.
The point being that they TRIED to think about a subject and they proposed a thought or argument. Aint nuthin' wrong with that, even when half wrong. Besides, economics is one of the few sciences that depends wholly upon human-behaviour - and in that manner there may be a theory to propose but ANY THEORY regarding economic behaviour is just supposition. Because unlike most sciences, economics depends upon Human Behaviour that is wholly unpredictable*!
But, shooting an economics prof down for what he said (and now regrets saying) is simply poor-play. It the work of someone who actually has nothing more intelligent to propose in the debate ...