Remember that Elop is not only Microsoft and WP, but also "Internet for the next billion" and a strong focus on Qt and QML. Removing Elop could also endanger those strategies. If Elop really wanted to kill the N9, he would have done this, IMHO, instead of splitting the world into WP and Symbian/MeeGo markets.
He most probably killed the first N9 design because it had serious issues and called people back to the drawing board to make sure the MeeGo phone will rock.