If UM sues the NCAA,they could put the investigation on hold until the court case is settled. This would drag it out for a longer period of time than if UM lets the case go forward through the regular channels. Think about how long it takes to get a civil case heard with the current logjam of cases. This is not a simple case with just several witnesses, but would be a complex case involving getting depositions from almost everybody that has anything to do with the investigation.