I would rather they hire a new OC, someone who has experience and has had success elsewhere. Even if that coach is coming from a lower division school it would have to be better than what Detmer has produced. If they are going to retain Detmer, then they need to hire a good QB coach so Detmer can focus 100% on fixing this mess of an offense.
I also wouldn't mind either demoting or firing Tuiaki and bringing in Gary Andersen as DC. The guy has had success as DC at both Utah and Utah State, has head coaching experience, and knows the state of Utah.