Yup, disk arrays can be quite a problem when it comes to forensics recovery. This has been a bit of a nemesis of mine over the years. Friends or family will decide to buy a single RAID solution for backup and configure it to write files across the disks for performance because they don't know any better. Four years later they'll come to me because something happened to the array like a failed or corrupted controller NVRAM and they want to recover the files. For backup I recommend mirrored single individual spinning disks, preferably in multiple locations.