The argument posted in your link seems best summarized as: "China had virologists and biologists studying coronaviruses and that is suspicious." It even admits in the first paragraph it has no evidence of a causal relationship. We'd expect a country that is appropriately prioritizing domestic viral threats to be profiling things like coronaviruses in animals, so it seems odd to count this as evidence.

Unless I missed some key evidence in the text, it seems like the entire animus of this argument was that the Chinese government would be inclined to lie if the virus did escape from a lab, and since they said it didn't happen, that must be true.

Doesn't that make it a simple conspiracy theory? I get that Americans are inclined to believe governments lie about these things, (after all, the US covered up its H1N1 strain outbreak by calling it "Spanish") but if we're trying to evaluate things in terms of evidence and probability, this argument seems contrived.