https://www.siliconvalley.com/2020/06/30/tesla-ceo-musk-wrong-about-coronavirus-testing-uc-berkeley-expert/

Tesla CEO Elon Musk, who has called stay-at home orders fascist and defied local officials over re-opening his Fremont electric car factory, was incorrect when he tweeted that high rates of false-positive Covid-19 tests help explain why the number of positive cases is rising while deaths and hospitalizations are falling, a UC Berkeley infectious-diseases specialist says.

Musk on Monday tweeted, “There are a ridiculous number of false positive C19 tests, in some cases ~50%.” He added, “This is a big part of why C19 positive tests are going up while hospitalizations & mortality are declining.” And, he suggested to his 34 million followers and other Twitter users, “Anyone who tests positive should retest.”