A UK diver wants $190m (£145m) damages from Elon Musk for a tweet calling him "pedo guy", a US court has heard.
Vernon Unsworth, who helped rescue 12 boys trapped in a Thai cave last year, is suing Mr Musk for defamation.
He asked a jury in a Los Angeles federal court to award him $150m in punitive damages, as well as $40m for assumed and actual damages.
Mr Unsworth's lawyer Lin Wood said the award would be a "hard slap on the wrist" for the Tesla co-founder.
Calling Mr Musk, 48, a "billionaire bully" in his closing statement, Mr Wood told the court that his client's modest life had been upended by the very public row.
"He dropped a nuclear bomb on Vernon Unsworth," he said, adding that the "fallout" would impact on him for the rest of his life.
Mr Musk's lawyer, Alex Spiro, responded that the tweets were the result of an argument between the two men.
"In arguments you insult people," Mr Spiro said. "There is no bomb. No bomb went off."
How did the row start?
The case of the Thai boys, members of a football team who were trapped deep inside a cave in northern Thailand, captured the world's attention in June 2018.
Mr Unsworth, a 64-year-old experienced cave explorer, splits his time between the UK and Thailand. During the rescue, he helped recruit experienced cave divers who were instrumental in freeing the boys safely.
Mr Musk sent Tesla engineers and a small submarine to help with the Thai rescue effort, but it was never used.
Instead, he and Mr Unsworth got into a public war of words after the diver dismissed the offer of help.
Mr Unsworth labelled the submarine a "PR stunt", and during an interview with CNN suggested the billionaire "stick his submarine where it hurts".
Mr Musk, who has 22 million followers, responded with a series of tweets about Mr Unsworth - including one calling him "pedo guy", which has since been deleted.
What has been said in court so far?
Testifying over two days on Tuesday and Wednesday, Mr Musk told the court he did not expect the "pedo" tweet to be taken literally.
He said that at the time he thought Mr Unsworth was "just some random creepy guy" who was "unrelated to the rescue".
Mr Musk apologised on Twitter and in court for his outburst. He also said the term "pedo guy" was a common insult in South Africa, where he grew up.
Contesting this, Mr Wood cited another now-deleted tweet the billionaire sent to his followers saying: "Bet ya a signed dollar it's true."
Then, in an email exchange with a Buzzfeed reporter who contacted him for comment on the threat of legal action by Mr Unsworth, Mr Musk said: "Stop defending child rapists."
On Thursday, Mr Unsworth told the court that Mr Musk's tweet left him feeling "humiliated".
Court reporters said the diver appeared on the verge of tears as he told jurors: "It feels very raw. I feel humiliated. Ashamed. Dirtied. Effectively, from day one, I was given a life sentence without parole. It hurts to talk about it."
He added: "I find it disgusting. I find it very hard to even read the word, never mind talk about."