Epidemiologist Ellie Murray said it better than I could, so I’ll just quote her: “Yes, the chance of a virus like SARS-CoV-2 suddenly arising is fairly low. That’s why we have so few pandemics!! But conditional on being in a pandemic the chance that the virus that arises to cause it is like SARS-CoV-2 is super high!! There’s no conspiracy, just statistics”[0] That said, the fact that the outbreak started so close to…
This statement is a distraction from the main question. The question is: conditional on being in a SARS-CoV-2 pandemic, what is the probability that the virus arose through purely natural processes, vs. the probability that it escaped from a lab.
I am not equipped to assess the biological evidence, but I do know this: The virus came out of Wuhan, the location of a top safety level (BSL-4) lab that experiments on coronaviruses. It is China's first BSL-4 lab, and one of a small group of such labs worldwide. This alone suggests that the probability of a lab escape is not negligible and should be taken seriously. In fact, without considering additional evidence I would argue this puts the probability of a lab escape above 50%. But again, I am not familiar with nor am I equipped to assess the biological evidence.
In addition, if the virus did escape from a lab, both the Chinese government and the bio scientific community are clearly and highly incentivized to keep this fact a secret. Therefore, when a member of one of these groups argues that this is not a lab escape, this serves as very weak evidence in favor of natural evolution. The incentive to keep such an outcome a secret is so strong, that I would argue we should discount such statements altogether and focus on the actual evidence.