"... for it is unacceptable, humanely and religiously, to dispose of a person with such importance and status among his people, by throwing his body into the sea in that way, which demeans and humiliates his family and his supporters and which challenges religious provisions and feelings of hundreds of millions of Muslims."
Is the issue of how to treat the dead body separate from the question of killing the man? Note the assertion that the treatment of the body is something that you do to the living. But why show respect to the people who are devoted to someone you marked for execution? And yet we did show respect for the body. Omar bin Laden's argument can only be that we botched our attempt at showing respect. I think he's using Alinsky rule #4: "Make the enemy live up to its own book of rules."