A federal court jury in Los Angeles has found in favour of Tesla boss Elon Musk in the defamation lawsuit brought against him by a British cave explorer he branded "pedo guy" on Twitter.
The verdict was delivered on day four of the trial on Friday, a short time after the case was handed to the jury of five women and three men.
The plaintiff, Vernon Unsworth, was seeking $US190 million ($A277 million) damages against Musk, who during the trial estimated his net worth at $US20 billion.
Musk, who testified during the first two days of the trial in his own defence and returned to court on Friday to hear closing arguments from the two sides, exited the courtroom after the verdict and said: "My faith in humanity is restored."
The case is believed to be the first major defamation lawsuit by a private individual to go to trial over tweets.
Unsworth's attorney L Lin Wood summed up his case against Musk by calling the high-tech entrepreneur a "billionaire bully" who "dropped a nuclear bomb" on Unsworth in a series of tweets suggesting he was a pedophile.
Wood said Musk's "pedo guy" remark was a slur that would overshadow Unsworth's relationships and job prospects for years to come and urged jurors to teach the Tesla chief executive and SpaceX founder a lesson.
British diver Vernon Unsworth (C). Source: EPA
But the jury, in its unanimous decision, was apparently swayed by the arguments put forth by Musk's attorney, Alex Spiro, who said the Twitter message in question arose from an argument between two men and amounted to an off-hand insult that no one could be expected to take seriously.
"In arguments, you insult people," he said. "There is no bomb. No bomb went off."
