Maybe their diagnosis was incorrect.
Just for general info, this is from the Lancet review of 5400 cases:
“Fever and cough are the most common symptoms in patients with 2019-nCoV infection, and most of them have abnormal chest CT examination.Some people have muscle soreness or fatigue, ARDS. Diarrhea, hemoptysis, headache, sore throat, shock and other symptoms only occur in a small number of patients.The mortality rate of patients with 2019-nCoV infection was lower than that of Severe Acute Respiratory Syndrome (SRAS) and Middle East Respiratory Syndrome (MERS).“