CALIFORNIA EVIDENCE: CIVIL AND CRIMINAL
...Privileges
......Waiver of Privilege
.........Waiver by Consent: Express or Implied
............Naming Expert as Witness
3 Cards On This Topic:

By injecting his mental state as issue in case, and calling expert to testify, D waived any challenge to unredacted contents of interviews on which E relied.

Disclosing expert as witness waives privilege re communications and reports relevant to issues on which expert is witness.

Discoverability of expert's reports and documents.