I admit, some of you come up with creative ways of taking morality out of the situation, good for you. There is the question of how you got into this kind of kooky hypothetical question, but whatever. The real question here is, would you do evil if you had no knowledge of the consequences? Does not knowing the consequences release you from them? I'm sure there's many people in the world, your Bernie Madoffs who'd pull that trigger in a second. People build their own walls around them. There is no escaping responsibility, and if he is offering you a choice and you take it, then it is you pulling that trigger and no one else. Are you willing to play god?
I'm amused but also a little frightened by how many of you are assuming things not in evidence, such as, does the man *have* a million dollars and will he keep his word? Are you in any danger of refusing the deal? And does knowing the identity of the person who may or may not be in the next room change the fact that you hold their fate in your hand? I'm also amused by the amount of people who want to "play the odds" that the person is someone they do not want to destroy or someone they do. If this person wants to screw with you, I'm sure anyone could be in that room, and worst case scenario, tied up and unconcious at point-blank range of your weapon. Accuracy not a factor. Even if you hit someone in a non-lethal area, then what? You're going to save them with your years of medical training? Who said there was a nearby hospital in the equation? You have to allow for worst-case situation.
Some have said to use the money for charity. This then becomes Kantian vs Utilitarian ethics. Is the potential good of the charity money worth the potential death of one human being?