St. Mark wasn't a patriarch, just a delegate who was a Metropolitan. He's talking about the patriarchs of Jerusalem, Constantinople, Antioch, and Alexandria, not the delegates present.@MichaelWitcoff AFAIK The only one to not sign the Council of Florence was St Mark of Ephesus, so if he was not the only Patriarch there, the statement rings untrue.
I can at least understand where the dislike for Dyer comes from, he comes across as arrogant, I can't comment on his content because I've never been able to listen to him for longer than 10 minutes. I prefer Matthew Raphael Johnson as an Orthodox lecturer/writer.