5.1 update downloaded to my Nexus 7, incorrect version number

Question

I got a notification today on my Nexus 7 (2013 version) that an Android update has been downloaded.

It's currently running Android 5.1, build LMY470.

The update screen says:

This software will upgrade your Nexus 7 to Android 5.1
...
Update size: 18.0 MB

I read an article indicating that the 5.1.1 update is coming out soon. Is the downloaded update really for 5.1.1, and the "5.1" in the notification is just an error, or is something else going on?

This article says that the 5.1.1 update is 18MB, which is consistent with what I have.

UPDATE 2015-07-08:

Something very similar has happened again. My Nexus 7 (the same one) is currently running Android 5.1.1, build LMY47V. I've received a notification for an update to Android 5.1.1, the same version. The update size is 18.0 MB. I applied the update; it now says it's running Android 5.1.1 build LMY48G. A Google search for "LMY48G" gets a number of hits, but few if any details about what's in it.

Answer 1

After a couple of days, I decided to go ahead and apply the update. It completed normally and the tablet is now running Android 5.1.1, build LMY47V, which is what's expected for the 5.1.1 update.

It looks like the only problem was that the version number was displayed incorrectly. I'm still curious about why that happened, and why I haven't been able to find any other reports of the same problem.

UPDATE 2015-05-26: I've received the update on my Nexus 4; it correctly shows the version number as 5.1.1. The update size is 18.1 MB.