I should think that common sense would answer this question. You square it like this:
Let's say a person in your company tells you their boss is sexually harrassing them. You're on reasonably good terms with both the accuser and the accused.
Some responses you might make in this case:
- Deflect. Pretend you didn't hear it. Or, if pressed: "This isn't something I know anything about. You'd better take that up with them. Or maybe you could talk to HR?"
- Express skepticism: "Well, I don't know if you're lying or not. Sounds like a he-said she-said situation. Sorry."
- Express emotional support: "That sounds terrible! I'm sorry you're going through this, and I appreciate that it must be very hard for you to talk about this. How can I help?"
- Provide logistical support: "Let's get to the bottom of this."
- Express complete solidarity: "That bastard! We're going to nail them right to the wall for this. Right. To. The. Wall."
- Express complete solidarity for the accused: "How could you say this about them? They're a good person! They would never intentionally harass you. It must be a misunderstanding!"
Now: which responses might fall under the sentiment of "please believe women"? Which wouldn't? Which responses violate your ethical norms?
Seems to me, if you're purely caught up in the legalism of the situation, I'm guessing your response is going to be "skepticism," whether you want it to be or not.