Oh it most likely did jump from animals to humans. Lab outbreak theory does not refer to the virus being artificial, but on that the jump occurred inside the lab due to bad measures and then leaked outside.
As to a natural virus being accidentally leaked from a lab, there's no evidence for that scenario, except for the fact that the first major SARS-CoV2 outbreak happened in the same city. For what it's worth, this is not as implausible a co-incidence as might be claimed, since it is not uncommon for a virology lab to study viruses endemic to the region it is located in.
The bat virus that seems to be the progenitor of SARS-Cov-2 was isolated in caves in a different part of China, quite far from Wuhan. Plus, bats hibernate during the time that the spread began.
https://www.scientificamerican.com/article/how-chinas-bat-wo...
So it's certainly not a recent transmission, which is why an intermediate host is proposed, which could also be bat, or some other host species. Coronaviruses are endemic in that region of China.