As you said earlier there's no right answer.. i think there's no right option shortlisted in the question too.. :)
Why would he (Judith Jarvis Thomson) give only one option where there could be altleast one alternative more to it..? Can't we just save those 5 by sliding a big stone, instead of a fat guy, infront of the train or by something else.. :)
RE: DILEMMA...UNCERTAINTY...DOUBTS?