Just like all the other previous cases I've seen, the author is arguing that wealthy people who buy luxuries instead of donating to charities to save impoverished kids are just as guilty of the deaths of children from starvation as someone would be if they made a conscious decision let a child die so they could satisfy their own desire for a luxury. They use this example:
Bob is close to retirement. He has invested most of his savings in a very rare and valuable old car, a Bugatti, which he has not been able to insure. The Bugatti is his pride and joy. In addition to the pleasure he gets from driving and caring for his car, Bob knows that its rising market value means that he will always be able to sell it and live comfortably after retirement. One day when Bob is out for a drive, he parks the Bugatti near the end of a disused railway siding and goes for a walk up the track. As he does so, he sees that a runaway train, with no-one on board, is running down the railway track. Looking further down the track, he sees the small figure of a child playing in a tunnel and very likely to be killed by the runaway train. He can't stop the train and the child is too far away to warn of the danger, but he can throw a switch that will divert the train down the siding where his Bugatti is parked. Then nobody will be killed - but since the barrier at the end of the siding is in disrepair, the train will destroy his Bugatti. Thinking of his joy in owning the car and the financial security it represents, Bob decides not to throw the switch. The child is killed. But for many years to come, Bob enjoys owning his Bugatti and the financial security it represents.
The author of this piece stats that "Bob's conduct, most of us will immediately respond, was gravely wrong". Most people responding probably don't have the first clue about trains either. Any sensible railfan will likely tell you that while Bob's motives were not pure, he did exactly the right thing.
Firstly, this example is beyond implausible. Trains don't just run away with no-one on board, and in the one-in-a-million chance that a train does somehow "escape" without any control, modern signalling and train control systems mean that an engine would be immediately dispatched to chase it down and the likelihood of it ever reaching some isolated tunnel that a child can access is almost zero (think about it: tunnels on busy routes are not easy to reach and the child would likely have already been hit by another train anyway). What's more, how does Bob know there's no-one on board? Just because you can't see anyone in the front cab doesn't mean there isn't anyone on board (you'd be very hard pressed to see if there's anyone in the cab if it's a high nose locomotive or running long hood first), especially if this were a rare runaway that has been caught by a rescue locomotive that is now coupled to the rear (this locomotive at the end, presuming Bob can even see the end of the train, would likely appear to be just another wagon from his perspective). So if you have people onboard the train, which is almost certain, you are condemning their train to crash and transferring the danger of death from one child to one (or more) railway workers.
But my main point of argument is relevant whether or not the train is an unoccupied runaway. In fact, it could be a loose rake of wagons without a locomotive and this point is still relevant and in and of itself justifies not throwing the switch. Bob does not know what freight the train is carrying. When that train sails off the end of the siding, the derailment is going to be destructive, and if it happens to be carrying any dangerous substances (especially volatile chemicals), the destruction's going to become even more impressive and spectacular. It could potentially kill Bob and the child and anyone else nearby and cause significant environmental/infrastructural damage (such incidents have occurred before). Suppose the runaway does have a locomotive - it's almost certain to be a diesel of some kind, likely a diesel-electric, and even if the wagons are not carrying explosive materials, the engine itself could conceivably explode. And the wagons could potentially be flammable too, like boxcars made of wood. What's more, if the railway happens to be electrified, the wagons, upon derailing, may strike the catenary masts and drag down the overhead wiring. Anyone with basic common sense knows downed power lines aren't the safest things in the world. And the example doesn't tell us what, besides Bob's Bugatti, the train could hit after racing off the siding. Even if it is not flammable in any way, are there buildings? Roads? People?
And come on, trains are noisy beasts and the kid would almost certainly be attracted to this loud noise. To think it would continue playing obliviously and not move out of the way is ridiculous. The amount of unlikely events being combined in this scenario makes it completely implausible and not worthy of use. Its use borders on a poor joke if you know a bit about trains. Of course Bob shouldn't throw the switch. The potential dangers and deaths that could result from the trains derailment more than outweigh the potential loss of life if the child does not move out of the way in time.
I also have to point out one really silly point in the example: "since the barrier at the end of the siding is in disrepair, the train will destroy his Bugatti". It doesn't really matter if the barrier is a perfectly maintained brick wall! A runaway train is going to plow through any barrier. But then there are idiots in this world who think their truck can actually take on a fully laden freight train doing a hundred k's, so I'm not shocked some people seriously think a well-maintained barrier at the end of a siding can stop a train travelling at high speed.