Agreed. He also could have been avoiding the heat you sometimes get from the windows. Or he could have been sensitive to light for some reason.
But, to answer your question, I don't think the airlines have any written policy on who controls the window shade. But if I were asked for my vote, I would say it belongs to the window seat passenger. But I would hope it would be a consensus of the wishes of the seatmates.
Ultimatly, members of the cabin crew do have the authority to control any activity or dispute within the cabin as it relates to aircraft equipment and it's use.
[This message has been edited by PremEx (edited 08-05-2000).]