He's being extradited now, which means that it's US laws that apply now. I don't think this particular fact is evidence of any law breaking, unless the email the user sent said they were pirating the show. Because it's hard to prove that Kim knew what "Dexter" was, and even if he did, it's hard to prove he didn't assume it was uploaded legitimately (by Showtime, for example).

That said, there's a little more to it than just promptly addressing DMCA takedown requests. In order to be eligible for the DMCA safe-harbor, a company must not be aware of specific cases of copyright infringement on their website without taking some action agais them.