No you miss a trick, the sale was made to a new buyer..he has the Certs now….the borrowed shares have still to be returned to Blackrock….hence the short not covered.
but that is somewhat academic ..as the SEC do not enforce the short seller delivering the shares…..so I don’t think they even bother to Borrow the shares and that would also cost, so they save that cost as well.
Where the shorts are in trouble, is when they have to pay the dividend to the buyers and when the dividend is huge , as they will be this quarter, with the shares going against them…it should be game over…..they will be short covering into a mkt of no sellers, just more buyers looking for the Dividend…..