A federal appellate court has reversed an order dismissing an injured worker’s lawsuit against his employer’s sole stockholder after the Oklahoma Supreme Court said the statutory language of the state’s workers comp statute was ambiguous.

The appeal revolved around the scope of Oklahoma’s workers compensation regime, according to the decision published Tuesday by the 10th U.S. Circuit Court of Appeals in Denver.

Perry Odom, who worked for Penske Logistics in Oklahoma City, suffered serious, life-threatening injuries in July 2015, when a semi-trailer collapsed on him at work, striking his head. In addition to pursuing relief from the Oklahoma Workers’ Compensation Commission, Mr. Odom and his wife filed a diversity action in the United States District Court for the Western District of Oklahoma, alleging that the trailer’s owner, Penske Truck Leasing Co. L.P., negligently inspected, tested, repaired, serviced and maintained the trailer, and then failed to preserve evidence critical to their lawsuit, according to the court ruling.

His employer, Penske Logistics, did not own the trailer, but his employer’s sole stockholder Penske Truck Leasing did. Mr. Odom and his wife sought to recover from Penske Truck Leasing through the personal injury action in federal court, but the district court dismissed their complaint, reasoning Oklahoma’s workers compensation statute shielded both an employer and an employer’s stockholders from employee negligence claims arising out of a workplace injury.

The Odoms challenged the district court’s interpretation of the Oklahoma statute, and the federal appellate court certified the question to the Oklahoma Supreme Court.

The state Supreme Court found the state law’s language concerning the application of the dual capacity doctrine to stockholders was ambiguous. Under the dual-capacity doctrine, an employer who is generally immune from tort liability may become liable to its employee as a third-party tortfeasor, if it occupies, in addition to its capacity as an employer, a second capacity that confers obligations independent of those imposed on it as an employer.

A stockholder could be sued outside of the state’s workers comp regime if the stockholder possessed a persona independent from that of the employer and courts must determine the stockholder’s persona on a case-by-case basis, according to the Oklahoma Supreme Court ruling in March.

Given the state Supreme Court’s ruling, the 10th circuit reversed the district court’s order and remanded the case back for further consideration.

“To obtain immunity from liability under Oklahoma law, Penske Truck Leasing must prove more than mere ownership of Penske Logistics,” the federal appellate court said in its ruling. “As the Oklahoma Supreme Court explained, Penske Truck Leasing must prove it ‘possessed’ a ‘persona’ or ‘identity’ ‘not independent from’ Penske Logistics.”

A company spokesperson declined to comment on the ongoing legal matter.