There was an interview years ago with Hino where the interviewer brought up some of these weird twists that just don't make sense. Hino was a lot of the time writing and drawing for kids and as he said, "kids don't care or know about the adult world. To them adults make bad decisions and choices..." Well, that's the gist of it anyways. Basically, damn right the guy should have been thrown in some dark cell, but to a kid it would make sense he was released back upon the world to continue being a monster.