California Court Enforces WCAB Pretrial Evidence Rules in DPR Construction

A published California appellate decision underscores a basic but consequential rule in workers’ compensation litigation: Evidence omitted from the pretrial conference statement generally cannot be introduced at trial merely because the opposing party had seen it before.

In DPR Construction v. Workers’ Compensation Appeals Board (McClanahan) (2025) 111 Cal.App.5th 1136, the Third District Court of Appeal annulled a Workers’ Compensation Appeals Board decision after two medical reports were admitted even though they had not been identified on the parties’ pretrial conference statement. The court rejected the WCAB’s position that the error could be treated as harmless and ordered reconsideration without the reports.

Read the published opinion on CourtListener.

What Happened in the Shoulder-Injury Claim?

Alonzo McClanahan sought workers’ compensation benefits for a right-shoulder injury that he said occurred on July 25, 2017, while he was working for DPR Construction. He testified that he spent several hours moving approximately 200 twenty-foot-long boards and developed stiffness between his shoulder and neck. According to McClanahan, he mentioned the problem to his foreman and superintendent but initially declined to prepare a report because he did not believe the injury was serious.

DPR disputed that account. Three DPR employees testified that McClanahan did not report an injury that day, and a sign-out sheet indicated that he had checked a box stating he was not injured. The record also contained prior medical treatment involving McClanahan’s right shoulder and differing accounts of how his later symptoms arose.

The workers’ compensation judge nevertheless found McClanahan credible and concluded that he sustained an industrial shoulder injury. The judge relied on his testimony, treatment records, and the opinions of qualified medical evaluator Dr. McGahan.

The Dispute Over Two Unlisted Medical Reports

Before trial, the parties participated in a mandatory settlement conference. Their pretrial conference statement identified Dr. McGahan as the agreed qualified medical evaluator and listed his reports as exhibits. It did not list two earlier reports prepared by Dr. Hanley, a previously designated qualified medical evaluator.

Over DPR’s objection, the workers’ compensation judge admitted the Hanley reports because DPR had received them before the settlement conference. The WCAB later acknowledged that omitting the reports from the pretrial statement was an error, but a majority affirmed the result. It reasoned that the judge did not rely on the reports to find an industrial injury and that the judge retained discretion to admit evidence as a matter of due process.

The Credibility Explanation Was Sufficient

DPR raised a separate challenge under Labor Code section 5313, arguing that the WCAB failed to explain adequately why it found McClanahan credible.

The Court of Appeal rejected that argument. Section 5313 requires findings on the ultimate facts, a summary of the evidence received and relied upon, and the reasons supporting the determination. It did not require the judge to provide a separate, detailed explanation addressing every reason for accepting or rejecting a witness’s testimony.

Here, the judge identified the ultimate finding—that McClanahan sustained an industrial injury—and tied it to his testimony, the treatment records, and Dr. McGahan’s findings. That explanation was sufficient for review even though the record contained inconsistencies.

Why the Unlisted Reports Required Annulment

The result was different under Labor Code section 5502. In California workers’ compensation cases, discovery generally closes on the date of the mandatory settlement conference. If the matter does not resolve, the parties must identify disputed issues, witnesses, and exhibits in the pretrial conference statement. Evidence not disclosed at that stage is generally inadmissible unless the proponent shows that it was unavailable or could not have been discovered through due diligence before the conference.

The Court of Appeal held that the Hanley reports did not satisfy that exception. They were already available, but McClanahan had not identified them. The fact that DPR had previously received the reports did not eliminate the statutory disclosure requirement.

The court also rejected the WCAB’s harmless-error analysis. Relying on longstanding precedent, it explained that allowing undisclosed evidence whenever the opposing party cannot prove specific prejudice would weaken the pretrial rules and make the statutory consequence largely meaningless.

What the Court Ordered—and What It Did Not Decide

The Court of Appeal annulled the WCAB’s decision and remanded the matter for reconsideration without reference to the Hanley reports. It awarded DPR and its insurer their costs in the writ proceeding.

The court did not hold that McClanahan’s injury was nonindustrial or finally deny him benefits. It upheld the sufficiency of the judge’s credibility explanation while requiring the WCAB to reconsider the claim on a properly limited evidentiary record.

Practical Lessons for California Workers’ Compensation Cases

DPR Construction makes the mandatory settlement conference a genuine litigation deadline, not a paperwork formality. Before that conference, parties should confirm that every medical report, witness, and exhibit they may need at trial is specifically identified. Possession by the other side is not a substitute for disclosure.

The decision also distinguishes two concepts that are sometimes blurred. A WCJ’s credibility explanation can be legally adequate even if a party strongly disputes the factual conclusion. But the evidence used to reach that conclusion must still be admitted in compliance with the governing procedural rules.

For injured workers, employers, and insurers, careful preparation before the mandatory settlement conference can prevent an otherwise avoidable writ proceeding and years of additional litigation.

Current-status note: The opinion was filed on May 16, 2025, and certified for publication on June 11, 2025. It remains published precedent. Because the matter was remanded, the appellate opinion should not be described as a final adjudication of McClanahan’s entitlement to benefits.