I've been on the receiving end of a false complaint over 20 years ago while working at a shipping company. One of the other supervisors was aggressively trying to get me to dump my girlfriend and date her. When it became clear that wasn't going to happen, she filed a sexual harassment claim. No kidding.
Luckily, the facility manager knew what was going on. He had seen her pursuing me relentlessly.
BUT...
Because the complaint was filed, I still had to endure eight hours of sexual harassment training, "as a matter of procedure." Everyone knew it was BS, but I still suffered. Moreover, it was in my employee file, so it could have later been used to establish a "pattern of behavior."
Such bullcrap.