Check out the following link, and then consult with one of the excellent criminal defense lawyers who practice in California and list here on Avvo.com. Review their listings and how the answer questions like this, then select a few for a consultation. Good luck.
This information is offered for informational purposes only, as I do not practice law in your State. It is not intended as legal advice and you should not rely upon it to decide how to resolve this issue. No Attorney-Client relationship is intended or established by this response. You are faced with a situation where you need to consult with an experienced defense lawyer admitted to practice law in your State before you make any decisions as to how to resolve this issue.
The case cited by my colleague has to do with eligibility for parole, not a parole violation found by the parole board. The Board of Parole Hearings schedules and hears appropriate parole requests. If parole is denied the prisoner may re-apply one year later. Beyond that you'd have to hire a lawyer to consider whether the original prosecution was constitutional defective as in a habeas petition.
Your husband would have to file a petition for a writ of habeas corpus with the Superior Court in the county where he is incarcerated. There is a form available on the California Courts website (www.courtinfo.ca.gov) but a habeas petition is a pretty big task and he may want to hire a lawyer to represent him.
The California Board of Parole Hearings (BPH) no longer has an administrative appeal process for challenging parole revocations.
The Prison Law Office sells an excellent publication called The California State Prisoner Handbook, which answers many questions like this. It is available at a greatly reduced cost to inmates and parolees. www.prisonlaw.com