So what could we do to help that guy? Or the next guy? Or you, when you're next?
Unfortunately, nothing could be done to help that guy.
We live in a society where any man is automatically assumed guilty, on any accusation of sexual harassment.
And any false accuser is exempt from consequences, because this could be construed as blaming the victim, and is thus labelled as sexist and misogynist.
And the company has provided a textbook example of the above, in the way that it treated the individuals involved.
I hope I will never be in this situation, and I try to protect myself by conducting myself with any female colleagues in the most formal and business-like manner that I can.