I'm not sure he ever knew anything about anything. :^) And he's never been as entertaining as Giorgio A. Tsoukalos:Is such a thing even possible? Yes, it is.
Crash go the Chariots! Van Daniken at a certain point in his book wrote “I seem to remember the Bible saying....” regarding gold foil on the Ark of the Covenent.
Von D. could not even be bothered to open a book that is universally available book to verify and footnote a remembered statement in support of the central thesis of his book. Why would anybody need to ever take him seriously again?