I am not the user you responded to, but you are making a fairly egregious logical error. China is an authoritarian, autocratic state. It will never permit any incriminating evidence to surface. Arguing that hard scientific evidence is required for us to come to any conclusions is a de facto rejection of any scenario in which China, its provinces, or any individuals are culpable of anything. Ever. This is much closer to an ideological position than a logical or evidence-based position.
In these situations we rely heavily on intelligence services. For example, the German secret service has assessed an 80-95% probability that it was leaked from a lab in Wuhan and presented a report to then Chancellor Angela Merkel. [The assessment was later leaked and was published in a German Newspaper.](https://www.sueddeutsche.de/politik/corona-bnd-china-li.3217...) I think the German intelligence services are far better equipped, resourced, and have far wider access to sensitive and privileged data, than either of us.
In these situations we rely heavily on intelligence services. For example, the German secret service has assessed an 80-95% probability that it was leaked from a lab in Wuhan and presented a report to then Chancellor Angela Merkel. [The assessment was later leaked and was published in a German Newspaper.](https://www.sueddeutsche.de/politik/corona-bnd-china-li.3217...) I think the German intelligence services are far better equipped, resourced, and have far wider access to sensitive and privileged data, than either of us.