For reference, the letter written to the Governor of California is to invoke the provisions of Government Code 3612, which if used would cause an automatic 1 week cooling-off period so a Board of Investigation can convene and gather facts for the Governor. At that point, if the Governor concludes from those facts that significant transit disruption would occur, or there is a risk to public safety or welfare, the cooling off period can be extended by court order up to 60 days.
This proviso in law appears to have been added in 2012, as a trailer bill off the end of that year's Budget, that reorganized some parts of the state government.