The age of consent in the state of California is 18. Highest in the Nation.
These guys are toast, period, end of story, there is no defense, all the prosecution has to do was prove the event happened.
At that point the Defendants go to jail.
They do not pass go.
They do not collect $200.
Meaning the laws and enforcement of the laws are completely different from each other. Take a look at all the birth certificates issued to teenage mothers some time.