Montoya v. Superior Court

Montoya v. Superior Court (Feb. 28, 2025, G064459) ___ Cal. App.5th ___, 2025 WL 654642, ordered published March 21, 2025

The burden of proving causation may shift to a physician whose alleged medical malpractice is responsible for the absence of evidence proving causation.

Kimberly Montoya filed a medical malpractice lawsuit against Dr. Aaron Fowler, alleging that he negligently failed to order a CT scan, despite observing signs of potential stroke, at a time when she might have been a candidate for treatment to reduce the long-term damage from her stroke. Shortly before trial, the trial court denied Montoya’s request for a burden-shifting jury instruction on the issue of causation, and Montoya sought writ relief.

The Court of Appeal stayed the trial and issued a writ of mandate directing the trial court to vacate its order denying Montoya’s proposed instruction and to reconsider whether to give such an instruction based on the evidence introduced at trial. The court explained that the burden of proving causation may shift to the defendant when evidence establishes that the defendant’s alleged negligence makes it practically impossible for plaintiff to prove causation due to a lack of critical evidence. In such circumstances, “ ‘it is more appropriate to hold the defendant liable than to deny an innocent plaintiff recovery, unless the defendant can prove that his negligence was not a cause of the injury.’ ” Shifting the burden of proof on causation prevents a negligent defendant from taking advantage of the lack of proof resulting from his own negligence.

The bulletin describing this appellate decision was originally prepared for the California Society for Healthcare Attorneys (CSHA) by H. Thomas Watson, Peder K. Batalden, and Lacey Estudillo at the appellate firm Horvitz & Levy LLP, and is republished with permission.

For more information regarding this bulletin, please contact H. Thomas Watson, Horvitz & Levy LLP, at 818-995-0800.

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