Since the Twitter exchange, the lawyer said, Mr. Unsworth has been approached by a music producer seeking to represent him in book or movie deals and has participated in two documentaries about the rescue. “Nothing Mr. Musk tweeted got in your way,” Mr. Price said.

So far, Mr. Musk’s defense has rested largely on the claim that “pedo guy” is a generic insult common in his childhood home of South Africa rather than an actual accusation of pedophilia.

“It’s quite common in the English-speaking world,” Mr. Musk argued from the witness stand on Tuesday, the opening day of the trial. “I’m quite confident if you do a search, it will just say ‘creepy old dude.’”

Mr. Unsworth and his lawyers dispute that notion, arguing that Mr. Musk was actively trying to damage the explorer’s reputation. In an interview, Mr. Unsworth’s lawyer, L. Lin Wood, declined to say how much his client was seeking in damages from Mr. Musk, but added, “We believe the evidence justifies a substantial award.”

The final witness on Thursday was Vanessa Unsworth, Mr. Unsworth’s wife, who appeared in a recorded deposition. While they are still married, the two separated in 2013 and they have only limited contact. She said Mr. Unsworth might have come across as aggressive during the Thai rescue effort because “he was extremely concerned about getting the kids out” of the cave.

After the jury was excused, the judge said that it could find negligence even without malice.

Mr. Musk deleted the tweets in July 2018, explaining in a subsequent post that he had written them in anger.

Still, Mr. Musk later told a BuzzFeed News reporter in an email that Mr. Unsworth was a “child rapist” who had married a 12-year-old — claims that Mr. Unsworth vehemently denies.