Nigel,
Please see my email today in response to you on another thread regarding the three duties that make up the fiduciary duties of a non-profit Board member. The "Duty of Obedience" does obligate the Board to "obey" the mission, purpose and values of ICANN as set forth in the Articles and Bylaws (including those cited above), and to its status as a public benefit corporation. This is a fiduciary duty, and while it must be balanced by the Board members against the fiduciary duties of care and loyalty, it cannot be denigrated to the point where it is breached.
Greg