If the Chinese were a little more cooperative in allowing WHO investigators or inspectors into that Wuhan lab and get a better sense of whether lab safety protocols were followed or ignored, these intelligent assessments might be and sound a lot more definitive. "Best guess" summations, or hypothetical probabilities are the best we have to work with right now because China, being an authoritian, one-party Communist state, behaves and acts like they have something serious and earth-shaking to hide that will tens of millions people worldwide very, very angry and pissed at them.