I have no idea what idea he might have of UFO's but he knows the Bible (even the New Testament) backstory better than any other living authority. He specializes in the Dead Sea Scrolls, particularly the Book of Jubilees. The Book of Jubilees echos much of what the Book of Enoch has to say about fallen angels.
I think all of this comes back to fallen angels and their attempts to manipulate humans and the earth for their own purposes (whatever that might be).
You’ve gotten me off on a search to learn more. On interesting thing I came across is that Jubilees states that God granted ten percent of the disembodied spirits of the nephilim to remain after the flood, as demons, to try to lead the human race astray until the final Judgment.