This is from the 6th February. I think China were acknowledging drawbacks in the nucleic acid test even back then:
Computed tomography (CT) imaging has also been added as an auxiliary testing method in Hubei, according to the latest diagnosis and treatment plan by the National Health Commission released Wednesday.
This suggests that the diagnosis of the novel coronavirus in the province will no longer be solely dependent on nucleic acid test results.
"The nucleic acid test result is the gold standard for the final diagnosis of novel coronavirus infections, but those who have a negative nucleic acid test result may see positive CT imaging results," said Zhang Xiaochun with the Zhongnan Hospital of Wuhan University."