I believe someone said both UND and Montana were the last 2 at-large selections. If true, here's how this could have played out: Both UND and Montana (presumably, anyway) had larger bids than their opponents, but both also had inferior records. What would it look like if the committee gave both UND AND Montana home games against teams that had better records? There could have been an uproar with some schools saying, "Big schools can just buy a home game, so long as they are selected for the tournament, even if their opponent has a better resume." Then look at it the other way - both UND AND Montana go on the road. That scenario has a lot of missed revenue, since UND and Montana are both big bidders, so they probably don't want to go that route either. I suspect that the UND and Montana bids were pitted against EACH OTHER, and not their opponents. They gave Montana the home game because they (presumably) bid higher than UND (If this isn't the case, I would be even more upset, because then it was just a screwjob). If UND had outbid Montana (and I'm not saying that's what the goal should have been), UND probably would have been at home and Montana would have gone on the road.
I know there's precedent that big schools can and have bought home games, and I know that UND was trying to do that. I'm guessing Montana was also. Did either team deserve one? In my opinion, no. That's why seeding more teams is important for the integrity of the bracket.