A natural virus sample leaking from a center studying coronavirus was never really addressed. Nor was the concept of Gain of Function studies really addressed. Officially there were no GOF studies underway - but there had been requests for funding of GOF like studies - which were denied.
What concerns me is that researchers tend to piggyback data for new research proposals on existing grants. You all ready have the facilities, lab workers, cells lines, and reagents and other equipment - just run a few experiments to prove out the concept. What is the incremental cost to culture a few more plates of cells, run a few extra sequences?
This narrative had various claims: that Sars-cov2 contained bits of HIV (by crackpot nobelist Luc Montagnier), that it was released intentionally, that it was actually released several months earlier during the 2019 military games in order to facilitate spread and that it is a tool to cull the population of the globe.
This was debunked and is still debunked.
One problem with conspiracy theorists is that they have an extremely low accuracy requirement in order to consider themselves vindicated. Being on the mark right is unnecessary, even being in the ballpark right is unnecessary. For conspiracy theorists, being in the same galactic sector right is sufficient to consider it a win.
The theory that it is a lab leak, possibly but not necessarily involving gain of function research, and probably by accidentally hitching a ride on one of the researchers has appeared later. It has not been debunked, though it has not been prooven either. It is a plausible possibility.
It is not popular in pro-science circles, because should it be true, the popular reaction is that research should be baned because it is too dangerous which is a stupid stance equivalent to collectively burying your head in the sand.
It is important to distinguish the two though.
Here's a post from Jun 2020 where people are arguing both sides:
https://news.ycombinator.com/item?id=23660413
I'm pretty sure this is the debate I remembered, since I have 2 comments in that thread.