NAES Corp. v. SCI 3.2, Inc.

The standard of proof for a claim under the last injurious exposure rule is reasonable medical probability; medical certainty is not required to show an employer was the sole cause of an injury. Liberty Metal Fabricators v. Lynch Co., 295 Or App 809, 813, 435 P3d 810 (2019), adh’d to as modified on recons, 302 Or App 110, 456 P3d 691 (2020).

NAES sought judicial review of the Worker’s Compensation Board decision holding it responsible for a former employee’s worker’s compensation claim under the last injurious exposure rule (LIER).  NAES argued the Board applied the wrong standard of proof when it decided NAES was the sole cause of the worker’s injury.  NAES asserted that because the medical evidence indicated a possibility the injury was caused by the worker’s subsequent employer (SCI), NAES could not be held solely responsible for the injury.  In response, SCI argued that it did not have to prove to a certainty that NAES was the cause of the worker’s injuries.  The standard of proof for the LIER is a reasonable medical probability, not a medical certainty; an employer need not prove it was impossible for the last employer to have contributed to the injury in order to show that a previous employer was the sole cause of the injury. Liberty Metal Fabricators v. Lynch Co., 295 Or App 809, 813, 435 P3d 810 (2019), adh’d to as modified on recons, 302 Or App 110, 456 P3d 691 (2020).  The Court found that the evidence showed a reasonable medical probability that NAES was the sole cause of the worker’s injury.  Thus, the Court held that, although not proven to be a medical certainty and the possibility of contribution by SCI existed, NAES was the sole cause of the worker’s injury.  Affirmed.