When Kohei Uchimura heard he’d tested positive for COVID-19, the three-time Olympic gold medalist was shocked.

“When I was first told I was positive, I didn’t believe it at all,” he said, recalling his initial reaction to the result of a PCR test from Oct. 28 during a news conference on Saturday, one day before Tokyo hosts a four-nation gymnastics competition at Yoyogi National Gymnasium.

Uchimura’s initial disbelief was proven to be right in the long run. He didn’t have the virus. Subsequent testing, including of his original sample, revealed his first test was a false positive.