The more general point would be, be aware of the second order effects of changes you promote. For example, revocation of innocent-until-proven-guilty would almost certainly reduce the chances of people who have blown the whistle of being hired again, as they would present a much higher risk to prospective companies, regardless of whether their claims were true. The fact that they would blow the whistle at all would serve as a huge red flag.
Of course, I don't actually know the incidence of sexual harassment at workplaces, and have no idea whether false reports are even an issue. I strongly doubt they are, but I can somewhat understand male managers fear of them, given that they can ruin careers and marriages. As much as sexual harassment is a problem, I don't think assumption of guilt is an appropriate or long-term effective solution.
Here's a relevant scenario: I'm a man, I hold a managerial position and I have to choose between hiring another man or a woman as a one of my direct-reports. Let's say both contenders have the same qualifications, they're both equally fit for the job, but then, I, as a manager, start thinking that if I hire the woman she will then possibly think of filing a sexual harassment complaint down the line in order to take my job. Remember the "believe" part, which means that the sexual complaint doesn't even need to be backed by anything real, because most of the times after the complaint has been made public the damage is already done for me, as a male manager, no matter what the investigation finds (if it manages to find anything). So I choose the man over the woman as my direct-report.