A federal appellate court has upheld a win for medical diagnostic company Medtronic Inc. in a lawsuit brought under the Americans with Disabilities Act by an employee who claimed he was fired because of his weight.

In Tuesday’s ruling, however, the U.S. Court of Appeals for the Ninth Circuit punted on the question of whether morbid obesity is itself an “impairment” under the ADA by finding that the plaintiff, former Medtronic facility maintenance technician Jose Valtierra, couldn’t establish that his weight was the cause of his dismissal from the company.

“Valtierra admits he closed 12 maintenance assignments as having been completed when he had not done the work,” wrote Ninth Circuit Judge Mary Schroeder, adding that the plaintiff had worked for Medtronic for more than a decade always while weighing more than 300 pounds. “There is no basis for concluding that he was terminated for any reason other than Medtronic’s stated ground that he falsified records to show he had completed work assignments,” she wrote.

The Ninth Circuit decision upholds a ruling by U.S. District Judge Stephen McNamee of the District of Arizona who sided with Medtronic on summary judgment in the case. McNamee, however, had concluded that morbid obesity was not a physical impairment under the relevant Equal Employment Opportunity Commission regulations and guidance. McNamee held in accordance with appellate rulings from the Second, Sixth, Seventh and Eighth circuits that obesity itself couldn’t constitute a disability unless caused by an underlying physiological condition.

But at the Ninth Circuit, the EEOC filed an amicus brief arguing that the other circuits had incorrectly interpreted the agency’s rules and guidance and that obesity was “plainly physiological” in its effects. The agency contended that Valtierra had raised a genuine triable issue regarding whether his morbid obesity was an impairment, since his medical records showed his weight had adversely impacted several of his body systems.

Schroeder, however, concluded that the Ninth Circuit didn’t need to ”take a definitive stand on the question of whether morbid obesity itself is an ‘impairment’ under the ADA” since the plaintiff had failed to show “some causal relationship” between his alleged impairments and his dismissal.

Jessica Miller of the Zoldan Law Group in Scottsdale, who represented the plaintiff, didn’t immediately respond to a message Tuesday afternoon. Neither did Shawn Oller of Littler Mendelson, who represented Medtronic. Barbara Sloan, a lawyer from the Office of the General Counsel of the EEOC, and Bryan Neal of Thompson & Knight, who submitted an amicus brief backing Medtronic on behalf of BNSF Railway Co., both presented oral arguments when the case was heard at the Ninth Circuit in June.