Thought Leadership

Key Points:
• Always subpoena a claimant’s decade-long medical files immediately.
• Ensure medical experts are aware of a claimant’s comorbidities and whether they are being properly controlled.
• Review the literature relied on by the claimant’s expert(s) and expose any reliance on unrelated medical conditions.
• Remember to use the more stringent Duvall substantial cause standard when there is no identifiable work accident.

The Delaware Superior Court recently affirmed a major defense victory by holding that routine workplace evaluations do not constitute an identifiable work accident solely because they may induce stress. In Johnson v. Christiana School District, 2026 Del. Super. LEXIS 324 (Del. Super. Ct. July 16, 2026), the Court upheld the Industrial Accident Board’s denial of workers’ compensation benefits, clarifying that claims regarding occupational anxiety must meet a more rigorous causation standard than other workplace injuries.  Specifically, the Court explained that, absent an identifiable work accident, claimants must demonstrate that workplace stress was a substantial cause of injury under the Duvall standard, rather than relying on the more lenient “but for” test that typically applies. This decision illustrates how employers and insurers can shield themselves from claims involving occupational stress caused by normal work activities. 

Angelina Johnson (“Ms. Johnson” or “Claimant”) worked as a third-grade teacher for the Christina School District (“District” or “Employer”). Ms. Johnson was scheduled for a performance evaluation, which occurred twice a year. If a teacher consistently received a poor rating, they would be placed on an “improvement plan,” and failure to improve could eventually result in the teacher’s termination. However, throughout her career at the District, Ms. Johnson had never received a poor rating nor was she ever placed on an improvement plan. Ms. Johnson was given a day’s notice that the school’s principal would conduct an evaluation. That night she began experiencing back spasms and pain. On January 6, 2026, the day of the evaluation, Ms. Johnson suffered a spinal stroke, which left her a paraplegic.

At the hearing before the Industrial Accident Board (the “Board”), Claimant’s medical expert testified that the stress related to the performance evaluation triggered the spinal stroke.  Claimant’s medical expert relied on generalized cerebral stroke studies, only partially evaluated Claimant’s prior medical history, and never performed a physical examination of Claimant. The District’s medical expert testified that the stroke was unrelated to the work event. The District’s medical expert first explained that Claimant’s medical expert relied upon literature that linked stress as a cause to cerebral strokes, not spinal strokes. Second, the District’s medical expert pointed out that Claimant had an extensive history of preexisting comorbidities, such as poorly controlled diabetes and hypertension, and that the literature suggests that Claimant’s comorbidities are high-risk factors for both spinal and cerebral strokes.

The Board determined that there was no identifiable work event and thus applied Duvall substantial cause standard. The District’s medical expert was more credible than Claimant’s for two reasons: (1) Claimant’s medical expert’s opinions were unsupported by the literature; and (2) Claimant’s medical expert did not have a sufficient understanding of Claimant’s medical history. Relying upon the District’s medical expert’s testimony, the Board found no evidence that stress was the contributing factor to her stroke and, therefore, her injury was not compensable.

On appeal, the primary issue before the Court centered on causation and which standard should apply. Under Delaware’s Workers’ Compensation Act, typically, the “but for” standard is applied when determining whether an accident or injury is causally related. Under the “but for” standard, a work accident is compensable and causation is satisfied as long as the work event serves as the setting or trigger for the injury, regardless of pre-existing conditions or whether the accident is the sole or substantial cause of harm. Reese v. Home Budget Ctr., 619 A.2d 907, 910 (Del. 1992). However, when there is no identifiable work accident, the Duvall substantial cause standard is applied. Under the Duvall standard, an injury is compensable if the ordinary job stress is a substantial cause of the injury, regardless of any pre-existing condition, as established by the “usual exertion rule.” Duvall v. Charles Connell Roofing, 564 A.2d 1132, 1136 (Del. 1989). 

Ms. Johnson argued that the performance evaluation constituted a specific, identifiable event that triggered her stress, and thus that the Board should have used the more lenient “but for” test to asses causation. In contrast, the District maintained that the evaluation was a routine aspect of employment, not an “accident,” and that the board properly applied the more stringent “substantial cause” standard. The Court ultimately agreed with the District, concluding that the annual performance evaluation did not constitute a work accident and that the Board applied the correct legal standard. The Court emphasized that none of Ms. Johnson’s circumstances met the criteria for a work accident under Delaware Workers’ Compensation Act. Although Ms. Johnson experienced a distressing event at work, she failed to demonstrate a “work-related specific and identifiable, physical, and unexpected event.”

This case serves as a significant guideline for insurers, employers, adjusters, and defense counsel, underscoring the necessity of systematically reviewing a claimant’s long-term medical history when handling occupational stress claims. Practically, this decision demands that legal and insurance professionals rigorously document all relevant medical information to accurately evaluate causation and potential liability. Furthermore, it reinforces the requirement that the claimant must establish unmistakable evidence of an industrial work accident or, if such evidence is lacking, to argue that the Duvall substantial cause standard should apply. In practice, isolating pre-existing conditions and scrutinizing the medical literature cited by claimant’s experts may not only inform case strategy but can directly influence both settlement negotiations and litigation outcomes. As a result, this decision is likely to influence how future claims are investigated, defended, and adjudicated, promoting more stringent evidentiary standards for stress-related workers’ compensation cases.

Alexander is an Associate in our Wilmington, DE office. He can be reached at 302-552-4342 or ACLandolfi@mdwcg.com.