Cohen and colleagues suggested their results showed there could be many other unidentified coronavirus cases from before the disease was officially detected in Europe.
Could certainly be.
The so-called Spanish Flu epidemic of 1918, for example, has been traced back to France in 1916, and may even be slightly older.
Jonathan Ball, a professor of molecular virology at the University of Nottingham, said it was possible the results were due to lab contamination.
Entirely possible, yes.