Which brings up the question is it slander/libel when the things told about you are not specifically reputation ruining, just generally wrong.
In the US, at least, there are different rules for people based on whether they are "public figures" or not. Libel (for the record, slander applies to something you say; libel applies to something you print) laws generally say that if you are Joe/Jane Average, you can successfully sue someone for saying something wrong about you. If that wrong thing caused you harm, you can win monetary or other damages. If you are someone who is already "in the public eye" then in order to successfully sue for libel you must also prove that the publication knowingly printed false information about you.
This is why, for example, Richard Jewell was able to successfully sue the Atlanta Journal-Constitution when they incorrectly accused him of being the Olympic Bomber: they were wrong, he was a private shmoe, so the barrier of proof was just being wrong. It is also why Tom Cruise couldn't win against that German gossip rag that said he was gay: it was incorrect(?) but he couldn't prove that it was printed while the newspaper knew (or reasonably should have known) it was false. It's set up this way because there would be a major chilling effect on public discourse if, for example, a newspaper could be sued for reporting today on allegations of corruption by an official that seem credible but are ultimately proven false tomorrow.
Should he decide to sue, Nakamoto could probably make a good case that he is a private citizen rather than a public figure. Assuming, of course, that all this turns out not to be true in the first place, which is still very open to debate.