Two days ago I found my non-rooted Nexus 5 in my pocket asking me which language I like. It looks like it has been factory-reset, and I suppose that one of my corporate accounts has reacted on accidental lock-screen PIN input. (Having tried it today, I can't exactly understand how that was possible, but let's assume that's just the case.)
The problem (which I was not aware of that it IS a problem) is that I was offline (roaming) when I noticed. I needed my phone, so I skipped the Wifi setup because my phone just told me it could not verify my software was up to date. I'm on 4.4.4, so I knew it was up to date.
Then, even after logging in to Gmail, Play Store etc., I was unable to get the Google backup restored. Wifi passwords, apps, home screen layout, app settings, that kind of stuff. I suspected that the only possibility to restore a backup is when the phone is first turned on after a reset and I might have lost that opportunity. So I did another factory reset (this time near my Wifi) and voilà, I could login and chose to restore the backup.
BUT: this restore restored what I had installed after the first factory reset. Indeed, the dashboard says this:
No carrier
Last activity seen on: Sep 1, 2014
Registered date: Jul 10, 2014
LGE Nexus 5 o2
IMEI: xxx
Registered date: Sep 3, 2014
So there's two devices now, one the "old" from before the first reset (on Sep 1), and another "new" one which was probably created by resetting my phone without restoring the backup (on Sep 1), refreshed by my most recent reset with restoring the backup (on Sep 3).
That was a long intro for a short question: Is there any way to revert my phone to the state stored under that old "No carrier" entry? Unfortunately, I have found neither a way to delete one of these backups (for example, the new one) nor a way to even look at the data.