I don't think the grandparent was implying the AI would be controlling robot arms to mix things directly (or at least I didn't interpret as such), but it could very well sit in the network until it notices two dangerous compounds in the same machine, and trigger a breakage that causes a harmful mixture. Break a vial containing a virus, then break two more that cause an emergency evac and maybe that's enough to get something out there.
But what I garner is that AI/robotics led wet lab work is in progress. And hacking the AI running the wet lab to make a virus is definitely plausible as that seems to be one of the directions we’re going in the AI+biopharma space
But in the near future labs will be more automated I guess.
The other option you can try these days is maybe social engineering, impersonation, etc. where you try to persuade someone to do that for you.