The subject of Hachiken butchering a roadkill raised a fairly predictable reaction across ani-blogo-sphere, with Bateszi probably putting up the most polished response.
I was a sheltered city boy too and man, field-dressing is nasty (fur getting everywhere for one), but I don’t understand where the angst is coming from. Not viscerally, anyway. I remember once we caught a mouse in our apartment. We lived in one of those awful concrete high-rises that Japanese call “mansion” — what a joke — but mice can get anywhere. My mother didn’t want to stomp it or let me do it, so she put it into a plastic bag and threw it out into frozen garbage heap. Oh yeaaaah, that’s way more humane — or is it? What bullshit.
You still want to isolate yourself from animal blood when butchering, however. Deer carry all sort of nasty diseases and parasites, so until it’s well cooked — no contact! Heck it’s still unknown if its prions can jump species and turn your brain into jelly, AFAIK.
Japanese may have a different view on it, which is not necessarily better informed. For example, many old people in Hokkaido think nothing of drinking from wild streams, although it’s well known that Ecchinococus is in there. When asked, they say that the parasite takes 20 years to kill a human, and they aren't going to live that long. Yeah.