I took that as within their lab groups. As-in sitting with their group of 4 or so, they led the group work.
Honestly, whatever their motives, that kind of interaction is what group work is for. Having students that can lead and communicate with peers is invaluable.
This works great until someone rejects their advances and in retaliation the male student (who is auditing the class so they have no consequences for failure) sabotages the female student's labs and therefore their grade.
The professor was simply stating what they observed. I am extrapolating on the possible problems that'd arise in this environment and what I am suggesting isn't really that absurd.
As a male student during my years in undergrad, I had 2 different instances of team members/partners who outright stated they would not cooperate and would just fail the lab/project unless I did XYZ thing for them. In the 2 cases I remember it was basically "do most of my work for me" despite barely having enough time to complete my own portions. To add onto this, professors often repeated in my courses that "it's your responsibility to make group/pair work succeed" and that students would need to pick up the slack for any deficiencies in the team/pair. To their credit, I occasionally had professors who graded work per team member to prevent this type of leaching but often the answer the professor would give the class was that learning how to pick up the slack was just part of the course.
It isn't much of a leap to see this kind of "if you don't cooperate we can just fail" behavior from someone who already has no academic penalty for failure (as audits don't have final grades) and who joins the class explicitly to try to get laid.
