I'm pretty sure they'd have to have significant evidence that plans were stolen and shifted out of the country. California has some pretty strict laws on anything that prevents an employee from taking another job in the same field. Unless they paid out a $BOATLOAD$ of cash to keep the Engineer in question from taking another job, it may not hold up.
IANAL though, so who knows. In the end, if the Engineer in question is in China and never comes back to the US, I don't know that China would give him up. Especially given how public the trade war has started to become.
I'd had such big hopes for magic leap after Google invested in it and was secretly hoping that it would be something as revolutionary as the iPhone was, but now the cats out of the bag. I never understood how they convinced so many investors to put in so much money for something that is a little better than hololens (which too is arguable)
IANAL though, so who knows. In the end, if the Engineer in question is in China and never comes back to the US, I don't know that China would give him up. Especially given how public the trade war has started to become.