Some personal experience.
I was asked by my boss for a talk, as one of my assistants to lodge a complaint on me in a similar situation to the guy in question.
Luckily my boss was very fair and listened to both sides of the story before escalating to HR.
Long story short, the assistant was unhappy about me commenting on her job and made up a whole story about me harassing her on a specific occasion.
Luckily I had a few colleagues who were with me to prove my innocence.
Just don't jump into conclusion based on 1 side of the story.
