[Nogrod]

[Sauron] naturally had the One Ring, and so very soon dominated the minds and wills of most Númenóreans. (I do not think Ar-Pharazôn knew anything about the One Ring. The Elves kept the matter of the Rings very secret, as long as they could. In any case Ar-Pharazôn was not in communication with them...)

But Sauron was not of mortal flesh, and though he was robbed now of that shape in which he had wrought so great an evil, so that he could never again appear fair to the eyes of Men, yet his spirit arose out of the deep and passed as a shadow and a black wind over the sea, and came back to Middle-earth and to Mordor that was his home. There he took up again his great Ring in Barad-dûr, and dwelt there, dark and silent, until he wrought himself a new guise, an image of malice and hatred made visible; and the Eye of Sauron the Terrible few
could endure.

It would not be the first or last time the prof wrote something at one time and contradicted it on another...