Earlier quoted context omitted.
I did the problems under the assumption that "pulling the lever" was an act, while doing nothing was not acting. Implied legal (and moral) liabilities made a difference in my choices.
Legally perhaps, but morally, I've never gotten why so many people think that the physical act of pulling or not pulling makes so much difference. It's a binary decision with two outcomes, in my personal view it is irrelevant which of the outcomes is caused by physical action and which by inaction (at least, supposing that you have enough time to think about what to do - obviously, if you have to react in a split sec…
What should you do? If you're going to take the view that failing to save a person you could have saved is morally equivalent to killing, then clearly you should kill your one patient to save the other five.
But think of the longer-scale effect this would have. Would anybody ever go to a hospital and get elective surgery knowing they might be killed to harvest their organs? A more general form of trolley problem doesn't necessarily present that exact dilemma with such clear consequences, but at any scale, think of the consequences of being concerned with what happens because of your inaction. Do you donate blood once a week or whatever the max frequency is at which your body can regenerate the red cells? Do you still have both kidneys? Do you ever spend money on anything except bare minimum shelter, enough grain to stay alive, and every other cent going to the AMF or whatever the maximum QALYs saved/dollar donated charity is? How many people have died in your time on Earth that could have lived if you'd done something different? If we all seriously made that a primary concern in our daily decision-making, virtually all productive action would be paralyzed. Everybody would be trying to become a hedge fund manager living like a pauper and giving all their money to the AMF, but the AMF would no longer be able to do anything, because everyone would be a hedge fund manager and there would be no one left to manufacture mosquito nets.