As already said, the reason Cecil did it was to not appear heartless to the players, and to show deep down he's not a mindless Dark Knight who has no feelings for anyone, but really cares about people, especially the love interest.
Besides as I learned in morality class at my catholic high school 2 years ago, appaerntly it's more important to let the world completly end and EVERYone die, then one innocent person die and everyone be saved. So quite obviously Cecil took some moralality and ethics classes in Dark Knight school. O.o
Also Maxx Power, excellent excellent site. *thumbs up* ^^__b