The geopolitical consequences of a 'lab accident' are so severe and existential that I'm doubtful that any evidence will come to light as China will do absolutely everything in it's power to suppress this information.
"Beijing’s joint research with the WHO “is completely insufficient as far as a credible investigation.”
"Instead, Beijing and the WHO agreed last summer to a series of scientific studies that were carried out in China. When the foreign members visited Wuhan in January, it was to help in a joint assessment of the evidence China had found, not to scour the city for new facts. “There was no freedom at all to wander around,” Watson has said."
This outcome would literally shape world history - it would change trade alliances, security posture, it might get them punted from the UN security council, it would severely tarnish China's ambitions for decades and the event would ring through history like 9/11 x 1000. It could very well start a war.
Can you imagine how the plebes around the world will react when they find out masses of their peers have died due to 'China'? That they've lost their livelihoods? There would be mass riots around the world, blood on the streets in a few places at least.
There's way too much at stake, I'm wary if we will ever find the truth.
If we do ultimately find out - the means by which is going to be conveyed will be a master class in Public Relations. How do you let a such a shocking bit of information out? I think it might be best to let rumours swirl first, then indicate 'maybe there is evidence' and only allow the final, official, judicial truth to come out once the plausibility has already been widely accepted.