Hangouts: How to make the phone dialer default (instead of the hangouts dialer)? Following a recent Hangouts update, when using Android 5 on Nexus 5, in an SMS conversation with a contact, touching the "handset" icon automatically launches the Hangouts dialer, while I would like to use the default phone dialer instead.

I did not find any option to change this back to the previous behavior.  Is this possible at all?
If you don't really need the hangouts dialer, you can disable it (as I believe it's now a separate app). Try: Settings -> Apps -> All -> Hangouts Dialer -> Disable.

If you can't disable Hangouts Dialer, you can uninstall it.  Hangouts will still function as normal.