You know you're winning

 when they change the argument.

All last year and as late as May of this year:

• "coronavirus came from a lab" is a debunked conspiracy theory

Now:

• what difference does it make where it came from, what matters is what we do to stop the next one.

The only response to the latter is to ask them why it mattered so much during the course of the previous year?  So much so, in fact, that you would be removed from Facebook, Twitter, and Youtube for talking about the lab leak theory.