It's not faulty reasoning, it's how probabilities work. I am estimating the probability of a lab escape given the above information, and without evaluating the biological evidence. It's a prior. By evaluating the biological evidence we can update this probability, but I didn't do that. I'm saying that because the prior is high, it is worth to go ahead and evaluate all the evidence. And I know that when experts who I respect looked at the biological evidence, they came to the same conclusion, namely that a lab escape is likely.