My understanding of the author's central thesis is this: the US, despite its world-class virology and disease study labs, regularly has lapses in procedure that regularly lead to situations in which the public might be exposed. Given that this is happening in our own backyard, we might reasonably expect countries of similar status (like China) to experience similar lapses. That reads as reasonable to me, but raises a…
It's purposely evolving diseases to spread faster or be more dangerous, for the sake of research. As I understand, it's at least a bit controversial. So maybe there's not as much of it going on as other research? If so, there probably wouldn't be as much opportunity for it to escape. But now that it has (per the hypothesis), it's ready to be very contagious right out of the gate. Thus, pandemic.