Did Elon Musk “try to take credit in any way for the rescue operation” that saved 12 young Thai footballers and their coach from imminent death in the Tham Luang cave network last summer? Did he deserve any? And if he didn’t, who did?

Those were the questions at the center of the billionaire’s second day of testimony in the defamation case brought by Vernon Unsworth, a British cave explorer, against the Tesla entrepreneur. Unsworth told the federal court in Los Angeles that Musk’s 15 July 2018 tweet calling him “pedo guy” made him feel “humiliated, ashamed, dirty”.

The court is considering if the tweet constituted defamation.

As jurors heard on Tuesday, Musk made his remarks after Unsworth mocked the miniature submarine that he had built and delivered to the rescue site. In an interview on CNN, Unsworth asserted that the underwater vehicle would never have worked, and suggested that Musk “stick his submarine where it hurts”.

Musk and his attorney, Alex Spiro, attempted to present the Tesla chief executive as sincere, self-sacrificing and modest when Musk took the stand for a second day on Wednesday. Musk denied he had ever sought to take credit for helping the cave rescue: “The pump and generator team deserve immense credit,” he said. “Nobody talks about them.”

Under cross-examination by Unsworth’s attorney, Lin Wood, one of the reasons for this came into focus, however. Musk was asked why he had used Twitter to apologize to Unsworth for the “pedo guy” remark, rather than contacting him directly or giving an interview on television. Musk said: “Most things I say on Twitter will generally get some press awareness … If I write something on Twitter, it will get reported.”

Indeed.

Wood introduced into evidence what appeared to be dozens of tweets sent by Musk documenting the process of building the submarine and delivering it to Thailand, including a video showing SpaceX engineers testing the tube in a swimming pool.

Faced with the volume of tweets that Musk had just admitted were likely to generate press coverage, the billionaire responded defensively. “I mean, I tweet a lot in general … I was looking for feedback from the public to see if there were any improvements they could suggest.

“I frequently solicit feedback on Tesla car design, even rockets,” he added. “We’ve incorporated quite a lot of feedback from Twitter on Tesla car design.”

Unsaid, but obvious to the members of the media who chased Musk out of the courtroom the moment he was dismissed, was that nobody was talking about the pump and generator teams because everyone was talking about Musk and his mini-sub.

Much of the rest of Musk’s testimony involved a close parsing of the degree of flippancy that should be accorded to “pedo” versus “pedo guy”, and further questions about Musk’s intent when he deployed the phrase against Unsworth.

“I did not accuse Mr Unsworth of being a pedophile,” Musk said.

Unsworth speaks

After sitting silently with his attorneys for the first day and a half of the trial, Unsworth took the stand on Wednesday afternoon to describe the impact of Musk’s words.

“When you combine ‘sus’ with ‘pedo guy’, I took it to mean I was being branded a pedophile,” Unsworth said with obvious distress, his voice breaking multiple times. “I feel humiliated, ashamed, dirty … I was effectively given a life sentence without parole. At times I feel very vulnerable. It hurts to talk about it.”

The 64-year-old Briton’s noticeable discomfort provided a striking contrast with Musk’s appearance that included references to the Simpsons, marijuana and his own net worth.

Unsworth said he had worked as a consultant on three books about the cave rescue, and appeared in two documentaries, for which he was paid a total of about $3,000.

His testimony will continue Thursday.

Ineptitude and heroism

The head of Musk’s family office, Jared Birchall, also testified on Wednesday about efforts to dig up dirt on Unsworth that might prove the cave explorer was actually a pedophile.

Birchall testified to hiring James Howard, without performing any due diligence. Howard was a private investigator who falsely claimed to have worked for Microsoft co-founder Paul Allen and the financier George Soros. Birchall’s own attempt to use a false identity while interacting with Howard was unsuccessful, but provided the jury with the opportunity to learn that he had previously used the pseudonym “James Brickhouse” to arrange travel for Musk’s family, help a Libyan refugee, and make inquiries about purchasing the domain name justballs.com.

A former wealth manager for Merrill Lynch, Birchall offered Howard a $10,000 bonus if he provided proof of “nefarious behaviour” by Unsworth. It was Howard’s fictional reports to Birchall that formed the basis of Musk’s email to a BuzzFeed News journalist falsely alleging that Unsworth was a “child rapist”.

The fourth witness to testify Wednesday was Richard Stanton, one of the undisputed heroes of the cave rescue effort. An internationally recognized cave diver, Stanton and his dive partner were the first to locate the missing boys in the cave, and Stanton directed the subsequent extraction efforts.

Musk and his lawyers invoked Stanton’s name numerous times, noting that the British volunteer had invited Musk’s contributions and provided guidance on what was needed.

“It is absolutely worth continuing with the development of this system in as timely a manner as possible,” Stanton wrote in an 8 July email to Musk that was introduced as evidence. In another email, the diver advised: “If you make a capsule that tightly encloses a 15-year-old boy it will fit through.”

On the witness stand however, Stanton paid tribute to Unsworth’s role in the rescue. “He was the first person to greet us and guide us through the chaos. He had the best knowledge of that cave … He guided us through the geography and culture.” Stanton also testified that Unsworth’s description and drawings of the cave passage were more detailed and valuable than other surveys of the area.

Under cross-examination, Stanton resisted efforts by Musk’s attorneys to diminish the importance of Unsworth’s contributions. The cave diver also spoke twice to reporters outside the courtroom on issues that he had not been able to testify on, due to objections by Musk’s attorneys and rulings by the judge.

Stanton was “acutely disappointed” when he saw photos of the submarine Musk built, he said, noting that the pod appeared to lack life-support, ballast or trim systems. “I realized it could not work.”

Asked whether he agreed that it was a PR stunt, the diver said: “I think he had well-meaning intentions, but there must have been a point when surely his engineers discovered it was not possible, and what happened from that point, when he decided to bring it on site and showboat … you can decide for yourselves.”

Stanton also said that Musk’s visit to the cave with a non-functioning mini-sub “detracted from the rescue effort” by taking up the time of rescue personnel.

Stanton addressed the media again after hearing Unsworth’s testimony.

“Watching Vernon being questioned is the first time I’ve really seen the impact on him personally,” he said. “I think it’s shameful Elon Musk isn’t here to be able to look him in the eye and see the damage that he’s caused.”

The trial continues.