(Adds comments from plaintiff's lawyer)
By Jonathan Stempel
Sept 16 (Reuters) - Elon Musk on Monday said he did not intend to accuse a British diver of pedophilia by branding him a "pedo guy" on Twitter, as the Tesla Inc chief executive sought to dismiss a defamation lawsuit.
Musk posted the tweet, for which he later apologized, after Vernon Unsworth accused Musk in a CNN interview of grandstanding by offering to help Unsworth's diving team rescue 12 boys and their soccer coach from a Thailand cave in July 2018.
Unsworth sued two months later in Los Angeles federal court, saying Musk falsely branded him a pedophile and child rapist, and denying those allegations.
L. Lin Wood, a lawyer for Unsworth, in an interview called his client "a good man whose efforts saved the lives of 13 people," and said he will reply to Musk's court filing discussing the tweet in three weeks.
"I'll keep my powder dry for now, but I can assure you it will be explosive," he said. He called Musk's motion "as offensive to the truth as was his original tweet."
Musk, 48, said "pedo guy" was "a common insult used in South Africa when I was growing up."
He said the expression was "synonymous with 'creepy old man'" and used to insult a person's appearance and demeanor.
"I did not intend to accuse Mr. Unsworth of engaging in acts of pedophilia," said Musk, who grew up in Pretoria. "In response to his insults in the CNN interview, I meant to insult him back by expressing my opinion that he seemed like a creepy old man."
Musk also said his "off the record" August 2018 email to a BuzzFeed News reporter to "stop defending child rapists" was based on an aide's summary of a private investigator's report on Unsworth, and that he did not then know the statement was false.
Unsworth has said he had shared a house in the Thailand countryside with a 40-year-old woman who owned a nail salon.
The dispute arose after Unsworth told CNN that a mini-submarine offered for the rescue from the Tham Luang Nang Non cave by Musk's company SpaceX was a "PR stunt" and Musk could "stick his submarine where it hurts."
In a related court filing, Musk's lawyers called Unsworth a public figure on matters related to the cave rescue.
They said this required Unsworth to show by clear and convincing evidence that Musk made his statements toward him with "actual malice," a high standard.
Unsworth is seeking compensatory and punitive damages. A trial is scheduled for Dec. 2.
Musk recently settled a U.S. Securities and Exchange Commission lawsuit over his Twitter use.
The case is Unsworth v Musk, U.S. District Court, Central District of California, No. 18-08048. (Reporting by Jonathan Stempel in New York; Editing by Tom Brown)