I think that most so call experts are just very skilled when talking and selling regular information, but nothing more.
A lot of online courses are just that, regular people with good enough (not master like) knowledge of a subject, presenting it in a "interesting" way and there you go, you can call yourself an "expert".
I didn't knew schools could fall for things like this, but that only mean his strategy is working.
What did the other teachers say about the guy?
Several of us talked to the administration about it. I don't think he will be back. It was so ridiculous that you either had to laugh or cry. Most of us chose to laugh... and do our best to make sure he won't be back.