When can Utah courts grant a new trial for expert disclosure violations? Peterson v. Hyundai Motor Explained

A recent Utah Court of Appeals decision highlights the importance of proper expert witness disclosures and clear jury instructions regarding burden of proof. In Peterson v. Hyundai Motor, the court affirmed a trial court’s decision to grant a new trial despite a substantial jury verdict in plaintiffs’ favor.

Background and Facts

The Petersons’ hybrid Hyundai Sonata allegedly caused a fire that destroyed their home and contents. They sued Hyundai for products liability, negligence, and breach of warranty, claiming a manufacturing defect in a high-voltage cable caused the fire. Two experts, Hodson and Palmer, initially identified one location (Point 1) as the cable pinch point in preliminary reports. However, at trial, both experts testified the pinch point was actually at a different location (Point 2), which had not been disclosed to Hyundai until the night before Palmer’s testimony. The jury awarded the Petersons $752,000.

Key Legal Issues

The case presented two primary issues warranting a new trial: First, whether the plaintiffs’ failure to timely disclose their experts’ changed opinions violated Utah Rule of Civil Procedure 26 regarding expert disclosures. Second, whether the jury instructions properly communicated that plaintiffs bore the burden of proof on their negligence and strict liability claims.

Court’s Analysis and Holding

The Court of Appeals affirmed the trial court’s grant of a new trial. Regarding expert disclosures, the court found that Palmer’s report clearly identified Point 1 as the pinch location, and during his deposition, Palmer confirmed he had disclosed all trial opinions. When experts later testified about Point 2 without proper supplemental disclosure, this constituted “surprise testimony” that violated Rule 26. Similarly, Hodson offered a new opinion at trial despite confirming at his deposition that he had shared all intended trial opinions. The court also found the jury instructions erroneous because they failed to specify that plaintiffs bore the burden of proof on negligence and strict liability claims, even though the breach of warranty instruction properly identified the burden.

Practice Implications

This decision underscores critical practice requirements for Utah litigators. Expert witness disclosures must be timely supplemented when opinions change, even if the change seems minor. The court emphasized that Rule 26’s purpose is “to preclude parties from trying to gain an advantage by offering ‘surprise’ testimony at trial.” Additionally, practitioners should not rely solely on Model Utah Jury Instructions (MUJI) without ensuring they clearly identify burden allocation. While MUJI instructions are helpful, they “do not necessarily represent correct statements of Utah law” and may require modification to clearly communicate which party bears the burden of proof on specific claims.