How to Approach Difficult Conversations in the Office When There's No HR

So, I work at a small, family-run business that has re-opened its office (we’re all vaccinated and we test for active infection once a week, mandatory). The other day, I overheard a manager from across the office talking about a high-profile sexual assault case to a newer hire, a young woman. It was so loud (to be fair, our office allows sound to carry pretty well) that I couldn't ignore it. The optics of this manager arguing the facts of the case (he was claiming it's too time-consuming to vet people in positions of power for past indiscretions) to a female subordinate incensed me.

There is no real HR and our operations officer is totally conflict-averse. How should I address this?