fwiw if that hadn't been the case and you had restored a none a9lh nand backup but was still on the decrypt9 screen (just incase someone else does this and searches for a solution),
(making sure you do not accidentally power down until this is done)
you could have pressed B to go back to the menu, pressed select to unmount the SD, then find and copy a pre 11.0 nand backup to your SD, pop the SD back in and restore that nand backup