> If it were a lab leak, there are probably a handful of eyewitnesses.

Not at all. The chances are that if it was a lab leak the people involved had no idea the leak happened at all. That's how lab leaks work: people make mistakes and inadvertently leak stuff from the lab. eg: Karen Wetterhahn vs lead

What you're talking about is a deliberate release from a lab, which would have eyewitnesses because they know what is happening and see it happening and can corroborate the reports of other witnesses. eg: Thomas Midgley Jr vs lead