U.S. District Judge Stephen Wilson on Tuesday denied Musk's request to dismiss the charges -- ruling that British explorer and cave diver Verson Unsworth, who Musk criticized, is not a public figure. The decision means Unsworth's suit will have a lower burden of proof in court when the trial starts Dec. 3.
The case stems from an offer by Musk to send miniature submarines to aid in the rescue of several trapped children inside a Thailand cave last year. Unsworth was critical of Musk's suggestion, which led to a public feud online in which Musk referred to Unsworth via Twitter as a "child rapist" and a "[pedophile] guy."
A September deposition showed that Musk suggested Unsworth might be "another Jeffrey Epstein" and the billionaire spent thousands on private investigators to find disparaging evidence against him.
Musk has said the term "pedo guy" was an insult and not to be taken as a fact -- and argued Unsworth is a public figure because of his involvement in the widely-reported cave rescue. Public figures must meet a higher burden of proof, known as "actual malice," to demonstrate defamation. "Actual malice" indicates a person knowingly expressed a falsehood.
In his 18-page decision, the judge ruled Unsworth is a private person and must only prove that Musk acted negligently in expressing his views.
Unsworth seeks damages from Musk in excess of $75,000.