"His actions against me do not justify my actions against him, and for that I apologize to Mr. Unsworth and to the companies I represent as leader", Musk said in a tweet. Sorry pedo guy, you really did ask for it. In an interview last week, Musk said he was reforming from his belief that Twitter was a no-holds-barred battleground where "if you attack me, it is therefore okay for me to attack back".
But while Musk also defended his donation by mentioning that he has donated almost $6 million to the Sierra Club, an environmentalist group fighting climate change, he is also helping keep fringe extremists in the Republican Party in power.
Anderson and others noted how Tesla has been at the forefront of electric auto development and reducing carbon emissions - and Musk's controversial Twitter comments could jeopardize that.
Unsworth, 63, who lives in Thailand, was among the first divers on the scene in Mae Sai after the boys from the Wild Boars football team and their coach became trapped inside on 23 June. That report came after some criticism of the plan from people who argued that the relatively large submarine would not be able to fit around the tight cave network the boys had to navigate.
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He also said Russian Federation "is a foe in certain respects" and that China "is a foe economically". When asked about who he sees as the U.S.'s biggest foe, he said that the US has "a lot of foes".
Musk must have realized the error of his way immediately after because he deleted the tweets, but its effects still ripple.
Tesla shares are down 3.7% this year. Earlier this month, Musk criticized the media for "negative" coverage of Tesla, and in May said he would create a site where people could rate the trustworthiness of an article and track journalists' "credibility score".
He had not had contact with Musk throughout the rescue operation nor since - a situation he hopes will not change. "The submarine, I believe, was about 5 feet 6 inches [1.7m] long, rigid, so it wouldn't have gone round corners or round any obstacles".
Musk responded by saying Mr. Osotthanakorn was "not the subject matter expert".
"This is the most brand-damaging thing Elon Musk has ever done", said Mr Roger Kay, analyst with Endpoint Technologies Associates who follows the technology sector. Reuters could not reach Unsworth for comment.
The episode also seemed to repel some of Tesla's closest backers, including alternative-energy loyalists who saw in Tesla a worthy opponent to the juggernauts of the oil and gas industries.