Good article. I saw this issue in academia about twenty years ago, and both the lack of just processes for both sides were appalling and even terrifying .
On the one hand, you are absolutely right: due process for all accusations, otherwise we might as well put go back to having witch finders on the public payroll.
On the other: the repeating pattern is that these cases involve a comparatively powerful, well-connected, high status (alleged) perpetrator and a lower-status person dependent on that first person’s goodwill, or at least vulnerable to that person’s displeasure.
In some cases, going through channels doesn’t work. In other cases, the victim sees the handwriting on the wall, or has been directly threatened by his or her assailant. Even people not involved hear that someone is a troublemaker or “crazy” and it’s seldom the high status figure.
It is analogous to breaking up organized crime. Yes, it is a job for the justice system, with its checks and balances. But people willing to testify are hard to come by, and we know the reason for that.