He isn't even the only athlete to compete knowing they had Covid:
https://en.wikipedia.org/wiki/Concerns_and_controversies_at_the_2024_Summer_Olympics

There was an outbreak of COVID-19 among aquatic athletes at the Games. On 24 July, it was reported that five members of Australia's women's water polo team had tested positive for COVID-19. Chef de Mission Anna Meares stated the cases were limited to the water polo team and that standard respiratory illness protocols had been put in place. On 29 July, British swimmer Adam Peaty tested positive for COVID-19 after displaying symptoms the previous day, before he took part in the 100 m breaststroke final, and Australian swimmer Lani Pallister tested positive on 30 July, pulling out of her race that day. Though it was not mandated, swimmers and coaches began wearing facemasks at venues. The confirmation of Peaty and Pallister's positive tests was followed by reporting later on 30 July that three other swimmers, two from the US and one from Romania, had contracted COVID-19, with the Americans having been relocated to a hotel.