Was there not a third choice for Alexander?
I've been playing through bioshock 2 for my friend and I've gotten to this point in the game. I swear back in the day when you got to the choice of killing or sparing Alexander, Sinclair would come on the radio and tell you that you could do an alternate thing of killing him that was more painful and that would give you a bunch of Adam. I can't find this option in game and googling it doesn't seem to find anything.