So someone can test positive, but have actually been infectious weeks ago. Rather than insist they then pointlessly self isolate along with their families it looks like a second test is suggested. So presumably the negative test over rides the positive. www.gov.uk/government/publications/sars-cov-2-rna-testing-assurance-of-positive-results-during-periods-of-low-prevalence/assurance-of-sars-cov-2-rna-positive-results-during-periods-of-low-prevalence
Am I reading this correctly?