I’m a long-time lurker and signed up just to comment here.
I went through the tiebreakers based on this hypothetical scenario and, outside of the matchups that have to go a certain way to make this scenario possible, assumed the favorites of the other PAC-12 games would win (since it would influence some of the tiebreakers). I was actually typing all of this out on the app and it refreshed when I went out of the app when I was almost done, and I just don’t have the patience to type it all out again. Anyways, Utah wins the tiebreaker among all 5 teams and then with the other 4 teams, USC wins.
So Utah would be the “home” team (1 seed) in the PAC-12 championship and would play USC.