"Based on the underlying genetic structure, we have already established that, if COVID-19 was the result of a lab escape, it was from gain-of-function research. "
This claim is illogical and does not stand. For example, a lab could have stored naturally occurring viruses that were then later leaked.
If the article is asserting that the virus could only have resulted from gain-of-function research, then why bother assigning a probability to it being naturally occurring.