[William Cloud Hicklin]

Hmmmm. You're right, there.

All the same, Sauron waited until ca. 2940 to begin searching the Gladden Fields. Which means... I'm not sure. It took him that long to learn of Isildur's fall? Not likely- surely all Gondor's history was in the libraries of Minas Ithil when he took it, and I'm sure he had spies among the Gondorians and/or Black Numenoreans and/or rebel Umbar. Just took him that long to expand his power from Dol Guldur?

But even so, there would have been no particular reason for Sauron to think 'Isildur's Bane' was the Ring- it could have been an arrow, or a scimitar, or his horse..... The forensic investigation of the scene was carried out by the Elves, not the recently-extinct Orc-band.

How likely would Sauron have been, really, to be aware of Malbeth's prophecy? Who knew of it, aside from the Wise and the cheftains of the Dunedain? And even if he did, would he have believed it? I'm sure the history of the Third Age was littered with Nostrodamuses, most of whom were spouting rubbish.