The Nebraska Court of Appeals Reiterates that Factual Determinations of Causation Is an Issue Largely for the Trial Court

by | Nov 2, 2017

The Nebraska Court of Appeals recently decided the case of Hamilton v. United Parcel Service, which affirmed a Workers’ Compensation Court’s order dismissing Hamilton’s petition with prejudice.

Hamilton was employed as a truck driver for United Parcel Service (UPS) for 12 years. In 2012, he went to the ER complaining of a headache, sore throat, and general discomfort, indicating he was concerned that he had been exposed to carbon monoxide. However, the ER physician determined there was no significant evidence of serious injury related to carbon monoxide exposure. Two months later, Hamilton followed up with his family doctor, claiming he had been exposed to carbon monoxide, smelled some funny fumes from the truck he was driving, and had a headache. However, his family doctor noted that carbon monoxide was odorless and that the headache could be related to high blood pressure. He began to demonstrate symptoms of dementia.

Hamilton ceased employment in May 2013 and filed his petition in September 2014, claiming his dementia was due to repeated exposure to carbon monoxide while working as a truck driver for UPS.

At the trial in November 2016, the court briefly heard Hamilton’s testimony, and noted that there was no dispute Hamilton was suffering from some sort of dementia because he was unable to communicate coherently for most of his testimony. The court also heard testimony from Hamilton’s family members, who noted unusual and marked changed behavior by Hamilton; Hamilton’s coworker about concerns in Hamilton’s behavior and issues with UPS trucks; and various experts, including an automotive engineer, occupational medicine expert, medical experts supporting the premise that dementia is causally related to carbon monoxide poisoning, a neuropsychologist, an industrial hygienist, and an industrial engineer/occupational health scientist. Upon completion of the evidence being presented, the court dismissed Hamilton’s petition with prejudice, stating that Hamilton “failed to prove he was chronically exposed to carbon monoxide so as to cause his dementia” and Hamilton appealed.

On appeal, Hamilton claimed that the workers’ compensation court erred by concluding he did not suffer a workplace injury because he failed to prove exposure to carbon monoxide caused or aggravated his dementia and in rejecting one of the expert’s testimony regarding causation.

The Court of Appeals determined that the lower court was not clearly wrong in determining the evidence presented by Hamilton failed to establish causation between any carbon monoxide exposure he may have had while employed by UPS and his dementia onset. The Court of Appeals iterated that Hamilton’s experts’ opinions were based upon his alleged chronic exposure to carbon monoxide, while admitting that they were unaware of the level or number of times to which he was exposed. The Court also stated that even if it was assumed that Hamilton was exposed to carbon monoxide, the lower court was unpersuaded that the dementia was caused by carbon monoxide exposure because there was no way to know the exposure or frequency levels. Consequently, the Court of Appeals agreed there was no causal connection established by Hamilton.

Hamilton also claimed that the compensation court erred by rejecting one of the expert’s testimony regarding causation, particularly that the compensation court rejected the expert’s testimony because he was unable to quantify Hamilton’s exact exposure to carbon monoxide. The Court of Appeals stated that the compensation court “did not require Hamilton to prove his exact level and frequency of exposure” but simply “pointed out the lack of any evidence demonstrating Hamilton was repeatedly exposed to carbon monoxide while at work” and “relied upon assumptions of exposure.” In its conclusion, the Court of Appeals stated that “an expert’s opinion must have a sufficient factual basis so that the opinion is not mere conjecture or guess” and that “[t]he value of an opinion of an expert is no stronger than the facts upon which it is based.” Consequently, the Court of Appeals determined the compensation court was not clearly wrong in rejecting certain expert opinions.

Therefore, it is important to remember: (1) a causal connection must be shown between the employment and the injury or disability; and (2) an expert opinion’s value is no stronger than the facts it is based upon. Oftentimes, we will see causation reports from treating physicians who simply do not understand, or have not been provided, the underlying relevant facts. Where appropriate, take the time to educate providers regarding relevant medical histories.

If you have questions regarding workers’ compensation cases, please contact Nebraska Workers’ Compensation attorneys, Zach Anderson, at, or Paul Barta, at, or (402) 475-1075.