I think we're pretty much on the same page here tbh. As I also was told, and believe, that being careful about the words "for cause" is almost always the right thing to do. I think it's pretty much only this series of steps that can get you into trouble:
1) Employee A claims that Employee B harassed them
2) Company doesn't put in any effort to hear Employee B's side of the story
3) Employee B is fired "for cause" for sexual harassment. Generally it's also not just the words here. It also comes with things like "no severance pay even though severance pay was typical for other fired employees."
4) It turns out that the original claim was bogus
In this specific scenario, the company could have problems.