I don't think it's controversial. Any country I've been to that can control ingress does control ingress and will promptly deport people who didn't enter the proper way.
Japan, S Korea, China, Singapore, etc., would be extremely hard for anyone to work off the books without having to resort to the underworld. Otherwise you may last a month or two, but most people will get kicked out without a visa. What's more regular police have the authority and responsibility to make sure anyone without a visa gets expelled.
This would be so rare that it'd be of little impact. That said, they would likely investigate who this person was, who originally employed them, and use those records along with any other trails left at points of entry and use that info to return the overstayer.
Japan, S Korea, China, Singapore, etc., would be extremely hard for anyone to work off the books without having to resort to the underworld. Otherwise you may last a month or two, but most people will get kicked out without a visa. What's more regular police have the authority and responsibility to make sure anyone without a visa gets expelled.