OK, my bad.

Thanks for the patient reminder to read the entire original post before jumping into commenting on the comments. I did in fact miss all the caveats about wheelchairs, light rolling, fat man being anaesthetised etc. Doh!

I guess elharo should also have stipulated that no-one has any avenging friends or relatives (or lawyers) in the entire scenario, and that the usual authorities are going to give a free-pass to any law-breaking today. Maybe also that I'll forget the whole thing in the morning, so there will be no residual guilt, angst etc.

To be honest, making the wheelchair roll gently into the path of the trolley is now looking very analogous to switching a trolley between two tracks: both seem mechanical and impersonal, with little to tell them apart. I find that I have no strong intuitions any more: my remaining moral intuitions are extremely confused. The scenario is so contrived that I'm feeling no sympathy for anyone, and no real Kantian imperatives either. I might as well be asked whether I want to kill a Martian to save five Venusians. Weird.