By Andrew Holleran It’s been an eventful offseason for Michigan football. Jim Harbaugh finally decided to announce his return to the Wolverines after flirting with the National Football League for about a month. However, that flirtation might have cost Michigan some key assistant coaches. Michigan has now lost both its offensive and defensive coordinators. Michigan’s defensive coordinator returned to the NFL earlier this year and offensive coordinator Josh Gattis just left for the same position at Miami. Many are blaming Harbaugh and his flirtation with the NFL for the latest loss. Uh oh… “Wel…