It was a terribly disappointing game, wasn't it?
I can't find too much fault with the offense, they scored 38 and though they could have scored more by cutting down on mistakes, that should have been enough for a blowout win. It was the D that stunk, and that's hard to explain, because Cosgrove is a competent big-time coach. Not great, but definitely competent.
Making things more puzzling, the Gophs were coming off a win against a bowl-winning squad. So we know they were good enough and talented enough to beat USD.
I don't know what you can say, except that these things do happen. Give Brewster the rest of this season and if you're still unhappy, bringing someone else. But keep this in mind for the sake of perspective: our Gophers, who some "experts" predicted would only win one or two games this year, is 1-1 with a win against a bowl team.