He called Vernon Unsworth a "pedo guy" in a tweet after he rescued all of those kids in Thailand and criticized Musk's plan to build a small submarine to get them out. That wasn't a joke, it wasn't meant to elicit a humorous response, it was clearly meant to defame someone. Notice that accusing folks of pedophilia has become a pretty common tactic for the right nowadays.

Calling someone a pedo seems pretty unhinged for a billionaire responsible for running major companies, it honestly surprised me how Musk would spend his public energy saying that kind of stuff, and especially when you consider the power dynamics involved, it's hard to interpret his actions as anything other than driven by insecurity. But I guess beauty is in the eye of the beholder.

I read this as a polite way of saying he's up his own arse, which seems accurate.