As most other authorities describe in greater detail--it doesn't matter who wins the race to the courthouse. The non-compete will be valid in whatever state was selected as choice-of-law, but the non-compete provisions will be invalid in California because California generally prohibits non-competes except in very limited circumstances (such as owners of the company).
Consequently, a non-California non-compete is not valid within the state of California, even if another state's court validates it. This means that so long as the employee remains within California, the non-compete cannot bar them from seeking further employment in California, even if it would otherwise violate the non-compete. However, by the same token, even if a California court invalidates a non-compete, it only applies within California--the non-compete may remain invalid in other states (depending on their laws regarding non-competes) if the employee were to attempt to seek employment outside of California during the term of the non-compete.
Consequently, a non-California non-compete is not valid within the state of California, even if another state's court validates it. This means that so long as the employee remains within California, the non-compete cannot bar them from seeking further employment in California, even if it would otherwise violate the non-compete. However, by the same token, even if a California court invalidates a non-compete, it only applies within California--the non-compete may remain invalid in other states (depending on their laws regarding non-competes) if the employee were to attempt to seek employment outside of California during the term of the non-compete.
See, e.g., http://ymsllp.com/news-and-publications/with-limited-excepti....