While we sit in our armchair, typing our arguments to a hypothetical situation which is extremely unlikely, i.e. the trolley problem, Izumi Shinichi is subjected to such moral dilemma, whether it is ok to kill, humans or parasytes. While we have all the time in the world, he did not have such luxury and had to decide for himself. However, these questions are not so easily answered. In the end, he made a choice, whether it is right or wrong, he may never know. But I think that's how it always is. The most common answer for these questions are: it depends.
