Hey mate, I can attest to having this issue and at least give an account. I went in last month reporting failure of my HDD, the genius assumed that "Oh the partition somehow got corrupt, this happens" and somehow got a new installation on there after telling me they were not responsible for any data loss. So for some cases, some people would've already lost all their data if they didn't have a backup.

It failed again minutes after leaving the store so I arranged another visit with a genius. This genius was more helpful and understanding and swapped the drive out. Unfortunately the new replacement drive matches these model numbers. Not exactly happy about having to visit a far away store for a third time.