Those things are pretty much unenforcable in California.

Are you sure? The non-competes about working for a competitor is un-enforceable, but what about the ones that ban directly approaching former colleagues?

As ocdtrekkie pointed out, the key point here is he was soliciting former colleagues while there were still current colleagues. Even California won't protect you there.

The one tool companies have at their disposal in CA is the prohibition of using your old company's trade secrets in your new job. Mostly that means you can't take customer lists with you, but you also can't use confidential information to lure away former colleagues.

What that means in practice isn't completely clear to me, though it may just be that you can't take the org chart.

EDIT: http://www.rhdtlaw.com/job-hopping-california-right/

A non-compete is a different agreement than a non-solicitation agreement. The former is categorically unenforceable in California. The latter is much more of a gray area and dependent on circumstances.

That isn't a non-compete. That's a non-solicitation, which is enforceable, at least civilly.

Not always.

Very high senior management have been held to a non-compete if it is very specific and time-limited.

Self-driving is quite specific right now. So, if they limited it to a year, it would probably work.

However, the issue here is things he did while still working at Tesla, not after.

The provision is actually a non-solicitation provision, which often goes hand-in-hand with a non-compete.

Not in California. You can't enforce a non-compete but you can a non-solicitation.