He ended up under the patronage of the Flavians.
Even though he wrote books, he never satisfactorily explained how these things happened.
It has even been suggested that the cave story was the basis for his supposed fabrication of the Masada suicides. But that turned out to be not a story after all — the ostraca used for the Masada lottery — with the surnames still visible — were excavated there in the second half of the 20th c.