I'm guessing a backup technically existed (to satisfy any requirements or boss's-orders to the "letter of the law"), but nobody bothered giving any thought to restoring everything from that backup.
Of course, a backup that can't be restored (or nobody knows how to restore) is more or less equivalent to not having a backup, so this distinction probably doesn't matter.
Indeed - "usable" backups - they are ones you've tested restoring from (recently enough to be assured they still work on the latest version of your system).
I _hope_ they don't have someone saying "we had a backup - it was on a RAID set!".
It would surprise me less to discover the reported migration from Oracle on Windows to Oracle on Linux was still partly done, and they were taking solid reliable useable backups - of the old not-yet-decommissioned windows db servers...
(For the record, I've made both of those mistakes (and more) in my career... Fortunately neither represented weeks of 24x7 remedial work by 100s of people.)
Damn I wish this would happen at the IRS. Tired of paying taxes to do nothing to help. Spend hundreds of millions on computer systems but they can't figure out how to do a backup.
Of course, a backup that can't be restored (or nobody knows how to restore) is more or less equivalent to not having a backup, so this distinction probably doesn't matter.
// always remember to test your restore plan