In the USA, that right applies to criminal prosecution but not civil cases.

In the courts, yes, but in an office?

EDIT: I should add that I am 100% for eliminating sexual harassment from the workplace (and in life), but unfortunately there's nothing that forces a company to give employees due process. I would guess that in most cases, even the appearance of inpropriety is enough to warrant termination for at-will employees.

[re: claim that due process includes the right to confront accuser]

> In the courts, yes

In the US, this is only true in criminal courts. Even when it reaches beyond company process to the courts, sexual harassment is a civil matter.

What if the facts can be independently verified ?(existence of material proof or witnesses etc)

I imagine the right process would be to receive a claim and investigate it. The initial report doesn’t need to pinned to a specific employee, and it can even be a bystander that way. If enough evidence rise from the investigation, outing the reporter doesn’t bring much to the table.

You’re right that it’s more tricky when it’s a “he says she says” situation, those would warrant more direct confrontation I guess ?

It’s not a criminal trial.

Meaning that people shouldn’t be treated fairly if prison time is not on the table?

There are principles that are only binding to the government, but worth following outside of the courtroom in a civilized society. Innocent until proven guilty is one of them.