h2h is first I believe, but if three or more teams are tied, the round robin comes into play. So if NU is tied with JUST USC, they win that tiebreaker, but if they're tied with Nebraska and USC and Minnesota, for example, then I believe it'll go like this:
Minnesota is 2-1, Northwestern is 2-1, Nebraska is 1-2, USC is 1-2. So Minnesota and Northwestern "win," and then the head-to-head puts NU ahead of Minnesota. Nebraska lost to USC, so USC would be third and Nebraska would be fourth.
Part of the reason we wanted Nebraska to win last night was to put them ahead of NU so that the NU loss doesn't hurt as much in a potential tiebreaker. Nebraska couldn't pull it out though, so they're down slumming with NU at 7-12 now.