A convenience store clerk who remembered selling a sexual enhancement product to LaShawn Merritt helped the Olympic gold medalist earn a stunning anti-doping victory, albeit only a partial one.

In a decision released Monday, a three-person U.S. arbitration panel declared that Merritt’s three positive steroid tests last fall and winter were caused by accidental ingestion.

Calling the clerk who provided details of Merritt’s purchasing habits “devastatingly convincing” and the evidence in Merritt’s favor “overwhelming,” the arbitration panel declared that Merritt should get a three-month reduction of the mandatory two-year ban for steroids use.