In a typical city the size of Wuhan, what are the odds it has some sort of viral research lab? If this happened in (picking a city at random...) Chicago, you could work backwards, find a viral research lab in say, University of Illinois, and make the same claim. "No link to animal transmission has been found, and the original epicenter was known to have a viral research lab. QED."
And no, the vast majority of cities do not have viral research labs.