>The lab leak would have to be covered up by the Chinese authorities and the WHO would some how have had to be in on it.

Indeed. There's another important bit that you seem to be missing.

Did you know that Peter Daszak, one of the "reputable international scientists" you speak of who helped investigate and author that report was himself the project lead for the US funded gain of function research at the WIV?

Who would be more inclined or in a better position to cover that up than him?