Legal Question in Civil Litigation in California

That depends. Not all information about your PI case is privileged. Unless you have somehow waived the privilege, I'd be very surprised if your former lawyer has a basis to get privileged information. But non-privileged information is probably fair game -- if he can show that it is relevant to his case against you. Your question does not tell us enough about the cases to know whether it's relevant or not.

You should get a lawyer to defend you in the libel case. It may very well be a SLAPP suit -- a strategic lawsuit against public participation. If it is, you may be able to get it dismissed. An order dismissing a SLAPP suit should also order the plaintiff to pay the defendant's attorney fees associated with the motion. If you don't have a lawyer, you are unlikely to win such a motion. And even if you do, you won't be able to recover attorney fees for your own work.

Even if the libel case doesn't qualify as a SLAPP suit, you may have other strong defenses which you might not recognize, or know how to present, on your own.

Feel free to contact me directly if you'd like to discuss your situation further.

Good luck.

I agree that you need to retain counsel here. There likely is information about your personal injury suit that is discoverable in the libel action, e.g., communications with opposing counsel, documents filed with the court, and the like. Of course, other information would be protected by the work-product doctrine and the attorney-client privilege.

All else being equal, going head-to-head with a lawyer in the courtroom is akin to going head-to-head with a professional boxer in the ring. An investment in legal assistance, if only on a limited representation basis, strikes me as an essential investment to minimize the risk of an adverse judgment.

You've already messed up by representing yourself. A smart attorney representing you would have already filed a special motion to strike at the outset (SLAPP) and been able to recoup your attorney's fees.

Do yourself a favor and get an attorney. You could end up making things worse.