I think you can still be a pretty good engineer and believe that a stabbing in SF is probably perpetrated by a random homeless person absent other information. It may have been wrong for him to jump to this conclusion, but I don't think it has any bearing on his technical skills.
> There was another example where he questioned the ethics of a place I've worked at. He didn't have a leg to stand on but he made public pronouncements.
Again you may be perfectly right, but this has nothing to do with engineering talent. Lots of great engineers are famously assholes (in various ways): see, Linus Torvalds, Richard Stallman, etc.
> Somebody who does that is not likely to be a good engineer. A good engineer waits for the facts to come in before reaching conclusions. He's clearly not level headed. I've seen loads of bad engineers who act like Musk in these circumstances. Sometimes they have good reputations in their orgs because overconfident narcissists sometimes get rewarded.
This is just not the case as any kind of rule. Like, sure, a perfectly rational Bayesian optimizer may not do these things. But real engineering at the highest level isn't about that - it's about intuition from experience about which system design choices will be good and which won't, and acting quickly and efficiently on that information.
The very small intersection of incredible engineers who are also very good people have the humility to quickly pivot when they've been proven wrong, admit it, and move on. Elon is obviously not in this category.
But I think you have to admit that it's telling that when pressed for examples of his technical failures in public, all you could come up with were completely non-technical examples.