Indeed but they did not use a easy and safe method.
They installed the insider app and used this to get GRD2. This can work but you need to do at least one hard reset and if you do not pay attention you need to use WPRT. So hardly a easy and safe method.
Not fully true, you'll have to hard reset if done wrong, then yeah, hard reset.
Steps to get Windows Phone 8.1.2:
*Download Windows Insider App
*Register for Windows Insider
*Open the app and select the fast ring
*Search for an update
*Once updated, UNINSTALL Windows Insider app before it has a chance to reregister
If it does get a chance to reregister and search for an update, then you'll have to hard reset to stay on Windows Phone 8.1.2, but if you do it while watching your phone, then your good to go.