You'd need to find that bat that you imagine bit someone in October 2019, swab its nose or anus and sequence for SARS-CoV-2, because the closest known bat virus

You'd need to find that bat that you imagine bit someone in October 2019, swab its nose or anus and sequence for SARS-CoV-2, because the closest known bat virus relative to SARS-CoV-2 has a decades-long evolutionary gap to it. Oh, also viruses don't get virulent in the new host the moment the zoonotic transfer occurs. It takes a bit of time to evolve and adapt.