Yeah, no. We know the genome of the virus, we know which family it comes from. The rate of mutation is just too big to realistically be random chance. The actions of the chinese clearly show that they know exactly what they are dealing with.
And in any case, it doesn't actually matter. Deliberate or accident, it came from China and China must be punished.
While I agree it was likely a bio-weapon, and that study seems to make some very strangely worded conclusions for a scientific paper giving me the distinct impression it serves more political purposes than scientific ones. Even if the article is totally accurate, this is only something that excludes genetic engineering, not an accelerated forced mutation process done by raising many generations of the virus in a targeted environment. This would essentially be mostly indistinguishable from natural evolution.
Still, we need to chill this type of revenge rhetoric. This could just as easily have been done by a 3rd party in order to try to entrap the US and China into a devastating war. This event fits the bill of an opening salvo in open kinetic warfare, and even if you don't live in the US or China, this isn't something that will end well for anyone if it happens.