That is your framing of the situation. Apple's framing is that he was plotting this while still working at Apple, and figuring out how to steal technology and take other engineers with him to start his own gig. His contract apparently says that he couldn't do that.

So yes. You can be sued for that. Obviously. Which is why he's getting sued.

You can be sued for anything, of course. A contract has to be enforceable for it to make sense to be sued for it, and California law has a lot of worker protections that make certain common contract provisions unenforceable/illegal. Nuvia's framing is that all of the things he did were previously held in court to be permissible under California law.

IANAL but my reading of the situation would be that apple has a better claim on his IP than the tactic they're taking. All they'd have to do is prove that the idea was formulated at apple and they never signed it over to him. My understanding of Cali law (albeit likely very flawed) is that this suit as written is not supported by law.

Even if the idea that is formulated is for a business that the employer isn't in, and left a decade ago (servers for data centers)? Or if the main idea is "I want to do my next chip design for someone else"? Doubtful.

Doesn't matter IIRC, most employers requires their employees to sign an agreement saying that anything they come up with during the term of their employment is owned by the employer unless the employer gives up rights explicitly. This is to prevent someone from getting "The next big thing" then running away to start a company for it even though their employer was interested.

You can be sued for anything.

Yes.

Whether or not the litigant prevails depends on specific language of agreements, their enforcability, and the specific circumstances around the departures.

Did the engineer decide to quit on their own or were they persuaded by someone who otherwise agreed not to poach?

Agreements not to poach are illegal. In fact, Apple itself was hit by a suit by the US Department of Justice over that: https://en.wikipedia.org/wiki/High-Tech_Employee_Antitrust_L...

The suit you are referencing was an agreement between major tech companies not to poach/recruit from each other.

The issue discussed here is an employee agreement that prohibits former employees from poaching current employees.

The text that Apple signed prohibited them from: "attempting to enter into, entering into, maintaining or enforcing any agreement with any other person to in any way refrain from, requesting that any person in any way refrain from, or pressuring any person in any way to refrain from soliciting, cold calling, recruiting, or otherwise competing for employees of the other person".

I don't see how it doesn't fit this case.

And this is more egregious (in Apple's perception, anyway): current employees poaching current employees.