## Facts

- Charles R. Bonds sued Dr. Mohan Roy for medical malpractice, alleging Roy negligently severed a major nerve during surgery, leaving Bonds with little use of his right arm and hand.
- The parties exchanged expert witness designations and declarations under California Code of Civil Procedure § 2034.
- Roy designated multiple experts, including Dr. Jan Duncan, whose declaration stated he would testify on damages.
- In deposition, Duncan said he was retained to evaluate Bonds’s disability and any pre-surgery disability based on records, and he did not expect to offer opinions on standard of care.
- On the last day of testimony at trial, Roy sought to have Duncan give additional opinions on (1) whether the injury was consistent with a cut nerve versus a stretched nerve and (2) the standard of care regarding immediate reoperation and consultation with a neurologist.
- The trial court denied the request as unfair surprise and prejudice to Bonds, particularly because Duncan was the final defense witness and there was no time to allow further deposition or preparation.
- Duncan testified only on disability and vocational opportunities; the jury returned a verdict for Bonds.
- Roy appealed the exclusion of Duncan’s expanded testimony; the Court of Appeal affirmed, and the California Supreme Court granted review to resolve a conflict about sanctions under § 2034.

## Issues

1. Whether California Code of Civil Procedure § 2034 authorizes a trial court to preclude an expert from testifying on subjects whose “general substance” was not disclosed in the expert’s statutory declaration.

## Decision

- The California Supreme Court held that § 2034 permits a trial court to exclude expert testimony on any subject not disclosed in the expert’s declaration describing the “general substance” of expected testimony.
- The Court concluded the trial court acted within its discretion in excluding Duncan’s late-proffered causation and standard-of-care opinions.
- The Court affirmed the judgment upholding the plaintiff’s verdict.

## Legal Principles

- California Code of Civil Procedure § 2034 requires an expert declaration to state the general substance of the expert’s expected testimony.
- A trial court may sanction noncompliance with § 2034 by excluding expert opinions offered at trial on undisclosed subjects.
- Exclusion is proper where late-disclosed opinions would cause unfair surprise or prejudice by denying the opposing party a meaningful chance to depose the expert and prepare cross-examination.
- Appellate review focuses on whether the trial court abused its discretion in enforcing § 2034’s disclosure requirements.

## Conclusion

The court affirmed that § 2034’s expert disclosure regime allows exclusion of expert opinions not fairly disclosed in the expert’s declaration, and it upheld the trial court’s decision to bar last-day standard-of-care and causation testimony offered beyond a damages-only disclosure.


Bonds v. Roy, 20 Cal. 4th 140 (Cal. 1999)