[Sparkle]

Given the very clear parameters of the problem set forth by the OP, I do view the ethical question as cut & dried: take action or do not take action. The bystanders' choice will have consequences either way.

The theoretical scenario reminds me of an actual situation I found myself in a few years ago -

I was driving in rush hour traffic on a four lane divided highway, the traffic was moving very swiftly (70+mph) but each lane was very congested. I was southbound in the passing lane, when I saw the the wheels of the car next to me turn suddenly towards me. The driver did not indicate and did not look over his shoulder to ensure it was clear and safe to pass. I saw very clearly what was happening and I had a window of about 3-milliseconds to make a decision:

Stay put and take the hit from the car coming in to my lane OR take defensive action and avoid the hit.

Unlike the theoretical situation we were given, I did not know with any certainty the consequences of my decision. But what I did know was that there were a LOT of people very close to us on the road the only clear thought I had was "minimize the damage".

I chose to take defensive action by pulling hard and fast to the left, I avoided the collision, and the other driver pulled himself back in to his lane. The cars closest to me were able to slow down and take their own defensive action to avoid becoming a part of the accident. Despite my very best efforts I was unable to regain control of my steering column and finally my car lost traction when it hit the gravel, rolled down the hill that divided north and south bound lanes, flipped over and crashed in a spectacular fashion.

I still have no idea what would have *actually* happened had he sideswiped me at 70mph but I am pretty certain, based on the laws of physics, that it would have resulted in a multiple vehicle accident.

I didn't make my decision because I have a hero complex or because I considered my own life more or less valuable than anyone else's. I made it because I had been given that millisecond of time when I could clearly see what was happening and had the ability to make a conscious active decision.

I don't believe that fate or the hand of god had anything to do with one drivers' careless action nor with my decision making process.

Making a decision and taking action was *to me* the right thing to do.