Why does McCoy decide he needs Khans blood when there are 72 other survivors of the Botany Bay onboard ship?
I've been asking myself that very question during the movie. Maybe it would have taken too long to unfreeze one of the other augments?
Does McCoy know whether it is any survivors blood or just Khans that can do the miracle ?
Did they really need Khan alive to give blood anyway - surely they could have scraped enough of Khans blood off the ground after Spock had finished with him?
Seriously though did Spock need the added complication of having to take Khan alive.