Unsworth was instrumental in the rescue of the boy’s soccer team, but lambasted Musk’s submarine plan in an interview published by CNN Friday. Among other comments, Unsworth said the submarine “wouldn’t have made the first 50 meters into the cave” and was “just a PR stunt.”

Musk, responding to further criticism from professor and New York Times columnist Zeynep Tufekci, wrote this morning that he “Never saw this British expat guy who lives in Thailand (sus) at any point when we were in the caves.” By “sus,” Musk may have meant “suspect,” implying that a British person living in Thailand is in itself dubious.

Musk went on to dispute Unsworth’s claim that the submarine concept was unworkable, saying that “we will make [a video] of the mini-sub/pod going all the way to Cave 5 no problemo. Sorry pedo guy, you really did ask for it.”

https://twitter.com/elonmusk/status/1018497953051258880

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Thailand does have a reputation as a nexus of child sexual exploitation, particularly by Westerners, but Musk offered no evidence for his allegation that Unsworth is a “pedo.” Because Unsworth was not a public figure prior to his recent rescue work, Musk’s tweet could invite a defamation lawsuit. Musk even doubled down on the unsourced claim.

https://twitter.com/elonmusk/status/1018513369404493824

Musk’s posts on Twitter have been increasingly vociferous and occasionally troubling in recent months. An early instance came last December, when Musk called a transit expert critical of his ideas “an idiot.” More recently, while speaking out against media reports on Model 3 production problems, Musk unknowingly endorsed a fact-checking site run by a predatory cult.

There has been no sign yet that others within Musk’s companies are pressuring him to tone down his public persona, and Musk has effective control of Tesla, reducing the ability of stockholders or dissenting board members to keep him in check.