IMHO the chicoms know it’s from the lab.
That’s why they’re freaking out.
No, the ChiComs are freaking out because this looks like it is going to be a kick in the teeth to their economy, plus there is the human angle for some. The Chinese in general still greatly respect their elderly - and that’s who’ll likely be hit worst.
Also... IF 2019-nCoV was from that lab, then that lab would have heads up info. on the pathogen, a vaccine, and so on. Their reaction says they DON’T have that.