One thing I did not realize is that US researchers who conducted gain of function research tried to downplay and discredit the possibility of the virus originating from the wuhan lab. There was an anti-lab theory Lancet statement signed by scientists, and "Daszak had not only signed but organized the influential Lancet statement, with the intention of concealing his role and creating the impression of scientific unanimity."
Plus there's all the stuff about the miners shoveling bat poop for weeks and then dying of coronaviruses, and the Wuhan institute collecting and doing gain of function research on these similar-to-SARS samples. And then several of the lab's gain of function researchers became ill in late 2019. And there's the weird renaming of samples to hide the unmatched closeness of the mine samples and covid. This is just the absolute surface of the article. There's too much to list here
Edit: here's another amazement for the list: "Shi Zhengli herself had publicly acknowledged that, until the pandemic, all of her team’s coronavirus research — some involving live SARS-like viruses — had been conducted in less secure BSL-3 and even BSL-2 laboratories." And the article says "BSL-2 [is] roughly as secure as an American dentist’s office."
There is _very_ high probability that this is just a human error.
The highest probability is this virus originated like every other virus in history.
For an epidemic to occur, you need not just a lab leak, but a population sufficiently naive to the pathogen. H1N1 was displaced by H2N2 in the late 1950's pandemic, which in turn was displaced by H3N2 in the late 1960s pandemic. Thus it hit the cohort of people aged 25-6 or less who'd never been exposed to H1N1.
I found an NIH article that says the likelier origin is that the 1950 virus was used to produce a weakened live virus vaccine candidate that lead to the reemergence and not an accidental leak. It also concludes by saying there has never been a likely lab leak epidemic ever observed.