I think this decision was hastened by news reports speculating that they wanted Ollie as their new coach:
http://www.espn.go.com/nba/story/_/id/12741477/oklahoma-city-thunder-fire-head-coach-scott-brooks
http://www.espn.go.com/nba/story/_/id/12741477/oklahoma-city-thunder-fire-head-coach-scott-brooks
