Why automatic downgrade to 7.0.434 ?

[Nemo]

There is one client that appearantly displayed a message that there is an update available. The user confirmed it (I was not around) and it installed an "update".
Unfortunately the update was a downgrade to 7.0.434 ... See the log attached. After the downgrade an error occurred because a log could not be created. Reinstalling 7.0.456 solved the issue.

Why did NR propose a downgrade at all?

On a side note: Usually the respective user has no rights to install software, but we need to start the NR Monitor with admin rights (in order to run it at all), so I guess that process was allowed to install the software.