Yeah, exactly what I was talking about. There is no way to say this just by looking at the genome, all you can do is to say that is not very probable, and that would still be a dubious claim. There is a plenty of gnome manipulations that leave no trace. Having said that, lab origin does not neccesarily mean genetic manipulation. Serial passage through animals (say, minks) will leave no trace of genetic engineering, but may make the virus contagius to humans (minks and humans have similar ACE2 receptor). Or just poorly handled sample from the would do.
That are all bogus claims. Biology doesn’t work how somebody not in the field in his simplistic theory think it does. The claims as written show a complete distance from the field and the necessary understanding needed to be able to even understand how wrong the claims are. Theoretically anything can be synthesized, practically, nobody would ever be even near to synthesize what we actually observe. Human controlled “passage through animals” would need many decades to produce the patterns. Totally wrong claims based on bad understanding of how that all works.
The open question is, again, what will be the percentage of such cases.