Keep in mind these things don’t really know anything. They’re good at saying things that seem to fit the situation because that’s how they’re trained. They are like that person you may know that thinks he knows everything and will just say stuff that sounds right to them. The only difference is the ai is a lot more practiced than the human. Google’s llm may have some filtering done on the output to at least make sure that all of the books it recommends are real though it wouldn’t surprise me if there’s a fake one in the list somewhere. These things are prone to “hallucinations” which some lawyers found out the hard way.

I read his book “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” about Oumuamua. https://en.wikipedia.org/wiki/ʻOumuamua it was well thought out and examines the object from many angles. He never says it was aliens. He only says that everything we know about it says it isn’t natural and could be aliens. He does say that it passed through so quickly that we really didn’t get a great look at the object and have to make some guesses about it based on observations.