It does indeed seem likely, but the evidence we have at this point is circumstantial. Until we have concrete evidence, stating it as fact is premature.
You're most likely not going to get concrete evidence from China. So, we go with the facts we have which all point to a leak in the Wuhan lab. If you have a better theory feel free to posit it. This is how science works, you draw a conclusion based on evidence. If other evidence disproves it then you change. The animal/bat patient zero theory hasn't produced any evidence.