Actually, Tom O'Connor DID hire Larranaga. TOC arrived at Mason in 1994, Larranaga in 1997.
I know many fault O'Connor for Larranaga's departure, but indeed he was instrumental in bringing him here in the first place, despite it essentially being a lateral move for Coach L (Bowling Green/MAC to Mason/CAA).
Relatedly, I remember President Merten saying that hiring Coach L was the best hire during his tenure and indicating that the other (apparently) assistant coaches being considered had "never called a time out".