The This Week In Virology podcast has been talking about the lab leak concept since the early days of the pandemic, with various experts opining on the likelihood. In [1], the expert discusses how the virus itself does not seem engineered; it’s most likely a naturally created virus. However, this is exactly the sort of virus that they study at the BSL4 lab in Wuhan, quite legitimately - and they produce good science…
No it isn't. The were studying SARS-CoV-1 and WIV-1.
They sequenced RaTG13 but that is too far away from SARS-CoV-2 with a thousand random mutations across its genome. And there's no evidence that they ever recovered culturable virus from RaTG13 or were able to culture it--there's a vast gap between sequencing a virus and culturing it.
We also know about their SARS-CoV-1 and WIV-1 work because they published it. Before the pandemic they had no reason to keep work on RaTG13 secret.
This is a case of Schrodinger's BSL4 lab. We know they built chimeras of other viruses because they told the world about that, we know they sequenced RaTG13 because they published that sequence, but there's a SARS-CoV-2 progenitor backbone that they found, which for some reason they picked to be the backbone in a new set of experiments, which they had perfect secrecy over and nobody has ever found any evidence of it.