From it:

- Even if Mullis had voiced a similar statement before his death in 2019, this quote does not mean the PCR test is unable to detect the presence of SARS-CoV-2 - the virus that causes COVID-19 - rather that it cannot determine whether the individual tested is infectious. -

Note the wording, 'Even if'. It tries to cast doubt on whether Mullis said what he did. No doubt hoping the reader wouldn't bother looking for themselves.