Moral hazard? Moral Hazard puts one in the way of making an immoral choice. Surely killing people to take their body parts represents an actual immoral action? I didn't miss a memo or anything?
One example of the potential moral hazard is that maybe there's some corruption (maybe there's some profit being made, and judges could get kickbacks on the number of times they execute prisoners).
And the quantity, youth, and low latency of organs for transplant exclude every possibility except harvesting.