How I took it is that there's only on place on the entire planet every day where these "mediators" are. And it's only in this one place where breaking a law causes the death penalty. People do not commit crimes simply because you never know where these mediators are that day. Wesley was in the exact wrong spot at the exact wrong time.
How does that work, how can you not know where the punishment zones are? The mediators were within jogging distance and they wear uniforms, how can you not spot them immediately and figure out that you're in a punishment zone? The Edo don't seem to have access to advanced especially advanced technology so I doubt a flower cam filmed Wesley's butt crushing it and alerted the mediator's office. It seems like the mediators just walk around and look for crimes ... in uniforms ... in plain sight.
This is so stupid it almost makes me angry, are the Edo just walking around thinking "Lalala, I'm going to have a massage, then sex ... whoa, why are these people wearing mediator uniforms running through the park, I HAVE NO IDEA WHAT THAT MEANS ... ok, after sex I'll have a drink, and then I listen to some music ... Lalala, what a beautiful day, I hope I don't stumble into a punishment zone, they should really tell us where they are, maybe I'll ask one of the mediators, I'm sure they must know where they are working today. I'm so smart!"