My problem is: right swipe is defaulting to internet calls instead of 'regular' calls.

First off, these are my relevant call settings:

as you can see I have no accounts and the internet calls are not enabled.

My contacts came from Google contacts (configured them online and then the phone got them).

After they came I used the "Mark as Default" function to select the correct phone number and emails and that's when things started behaving strangely. Doing a right swipe showed me this:

Instead of calling the contact 'normally'.

I started experimenting and was able to reproduce the bug using other similar contacts (contacts that I got from Google with 2 phone numbers + 2 emails). But if I created the Google contact locally (which would sync Ok with google) I didn't have any issues.

No other calling functions are affected: moving the phone to my ear still calls the correct number, direct dial widget still works.

My phone is a Galaxy S III running android 4.1 (but the same thing was already happening in 4.0), if that makes any difference.

What is causing this? How can I fix it?

Seems to be related to: How do I prevent "No Internet calling account" error? but I was still unable to fix it.