A federal appeals court upheld a lower court ruling against Duke University Health Systems in a case about who is responsible for liability payments in a hydraulic fluid surgical mishap.

The 4th U.S. Circuit Court of Appeals ruled 2-1 on Monday that the insurance company met its obligations with a $1 million payment to cover settlement costs related to a lawsuit involving two Duke-operated hospitals using hydraulic fluid to wash medical instruments in late 2004.

Duke wanted the insurer for the Automatic Elevator Co., Mitsui Sumitomo, to pay up to $6 million, according to court filings, for its role in the mix up when the hydraulic material was left on a loading dock and then resold as sterilization fluid.

U.S. Circuit Judge Henry Floyd determined that the elevator company’s “alleged negligence in leaving the barrels in its storage area constituted a single occurrence,” not one per elevator as Duke’s attorneys argued, making the financial damages for the company smaller.

The hospital settled lawsuits with patients potentially exposed to the contaminated surgical tools in 2008 for an unknown sum.