I'm pretty sure this is a psychological scenario to see what kind of a person you are. It reminded me of the id, ego and superego from college psychology courses---our three levels of thinking ranging from the impulsive id to the reasoning ego to the moral superego. This was Freud's way of explaining the human thought process, three different levels from our primal needs (id) to our super moral thought process (super ego) and the happy medium (ego) which we generally fall in daily reasoning.
Here's how my thought process between my id, ego and superego went on this topic:
Id: Of course! I could really handle being a billionaire right now and if it's some random stranger, it's not like anyone would know you were the cause.
Superego: That random stranger is someone's son who would be missed greatly.
Ego: Hold up, that random stranger could be a really bad person, probably some murderer on death row. You might be doing the world a favor.
Id: MONEY MONEY MONEY!
Superego: How could you live with yourself if you became a billionaire this way. You'd have regret with every penny spent, I guarantee it.
Ego: But I could really use the money. I'd use it well, be charitable, make the world a better place. I deserve this money more than a lot of other people who'd go for it without a thought!
Id: CARS! CLOTHES! MANSIONS! VACATIONS! EXOTIC PETS!!!
Superego: What if you were the random stranger and someone else was debating pushing the button?
Id: BUTTONS! LOTS OF BUTTONS! BUTTONS WITH CATS ON THEM. FOOTIE PAJAMAS!
Ego: Okay, I get it. This is obviously not real. The chances of me getting in this situation are probably less than a billion to one. This is just a test to see what kind of a person you are. It's not even real.
Superego: Good job, Eeg.
Id: MONEY BUTTON! WANT TO PRESS! CARS, MANSIONS, CATS, CLOTHES.....
Ego: Shut your pie hole, id.