Even if so, considering the length of incubation and allowing for a decent Ro, there were very very few cases of COVID-19 in the US in Dec-early Jan. If someone

Even if so, considering the length of incubation and allowing for a decent Ro, there were very very few cases of COVID-19 in the US in Dec-early Jan. If someone claims they had it at the time based on respiratory virus symptoms, the overwhelming odds are still on they having been one of the hundreds of thousands of symptomatic flu or similar cases, not one of the handful of COVID cases.