I had this issue too (stale nfs handles in optfs) back in late september and there was no way in restoring anything useful. I defintely was not backup-menu's fault as I didn't run it the day the fs broke. I could do a backup afterwards using plain tar command as root and tar was complaining about these broken files as they could not be read but the backup finished. Therefore you should have a close look at your (tar-)backup as it might be it's not complete!
In the end what you did was: overwriting the whole partition using the image-backup (all fs-errors are eliminated) and then overwriting those files that tar could read and save when using the tar-backup. All files not read are therefore as old as your image-backup.
As my optfs was completely messed up I lost a lot of data which was not backed up by hildon-backup. Handling with the images I backed up was also no option as the latest one was way too old.