Can expert witnesses offer undisclosed opinions when opponents choose deposition over report? Arreguin-Leon v. Hadco Construction Explained

In Arreguin-Leon v. Hadco Construction, the Utah Supreme Court addressed a critical issue facing trial attorneys: whether expert witnesses can offer undisclosed opinions at trial when opposing counsel chooses deposition over written report for expert discovery.

Background and Facts

Noe Arreguin sustained significant injuries when a sleeping driver veered off I-15 and struck the ladder on which he was working. Arreguin sued general contractor Hadco Construction, alleging it failed to implement required traffic control measures. Arreguin retained Bruce Reading as an expert witness on traffic control standards. Rather than requesting an expert report, Hadco’s counsel elected to depose Reading.

At trial, Reading testified about violations of engineering practices and regulatory standards. However, when Arreguin’s counsel asked about the effect a proper buffer zone would have had on the accident, defense counsel objected, arguing this causation testimony went beyond any opinion Reading had disclosed. The trial court overruled the objection, allowing Reading to testify that proper traffic control would have prevented the accident from occurring where it did.

Key Legal Issues

The primary issue was whether Utah Rule of Civil Procedure 26 permits expert witnesses to offer undisclosed opinions at trial when opposing parties choose deposition over written report for discovery. The plaintiff argued that choosing deposition meant the expert “is not so limited” compared to the constraints of a written report.

Court’s Analysis and Holding

The Utah Supreme Court affirmed the court of appeals’ reversal, holding that expert testimony cannot become a “free-for-all” simply because opposing counsel chooses deposition over report. While Rule 26 requires experts to be limited to opinions disclosed in written reports, the rule does not explicitly address deposition limitations. However, the Court explained that when parties elect deposition, they must ask necessary questions to “lock in” the expert’s testimony.

Critically, the Court found that Arreguin’s counsel made an incorrect blanket assertion that experts face no limitations when opponents choose deposition. The Court emphasized that disclosure requirements still apply regardless of discovery method.

Practice Implications

This decision clarifies important boundaries for expert witness testimony in Utah courts. Attorneys must understand that choosing deposition over report does not eliminate disclosure obligations. The ruling reinforces that parties deposing experts bear responsibility for comprehensive questioning to prevent surprise testimony at trial. Additionally, the Court’s harmless error analysis demonstrates that undisclosed expert opinions on key issues like causation are likely to be deemed prejudicial, particularly when the testimony provides a “logical roadmap” for jury decision-making.