Had he let the interviewer know, I assume he would have included that information in his admission, which he hasn’t.
What you call his “past actions” happened less than a month ago and relate to an ongoing pandemic. Sorry, but personal conduct has to come into the equation at some point, and not self-isolating when you’ve tested positive is beyond the pale in my book.
Or perhaps he wasn’t positive after all (see the link below), in which case the basis of his exemption is a lie.
Either way, he has behaved with callous disregard for others and doesn’t deserve to compete.
Tennis star Novak Djoković claims that he tested positive for the coronavirus on Dec. 16. But the digital test result suggests otherwise. This and a suspected false statement could create new visa problems for the athlete in Australia.
www.spiegel.de