I'm not going to defend what he said, but if you look at the interaction it clearly took two to get into a juvenile Twitter fight, the other guy was no paragon of class himself. That aside, while it wasn't OK for Musk to say that, the blowback was IMO indeed disproportionate. How many other millions of horrible but effectively inconsequential statements on Twitter are routinely ignored? The guy's livelihood wasn't ruined and Musk was roundly rebuked.

How many CEOs have made a public comment like that? Pretty much every other CEO of multi-billion corporations has the self control to stay out of petty Twitter fights. And you're right that it takes 2 to pick a fight, and in this case someone who was involved in the cave rescue and instrumental to its success was calling out someone who tried to swoop in and take credit as a PR stunt. Musk couldn't handle getting called out on his actions and threw a temper tantrum. To me the blowback was entirely justified and I think he's going to pay out a fat settlement for it.

When did the guy risk his life? he was just a consultant for the rescue effort.

I wanted to call you wrong, but it appears that I had confused him with someone else - I had thought that Vern Unsworth, who had this "issue" with Elon Musk, was one of the initial divers laying out the guidelines through the cave as he was quoted as "helping the Thai SEALs with mapping out the cave), however, the actual life-risking guideline setup was done not by him but by other British divers - Richard Stanton and John Volanthen.