Any more detail? There is a big gap between inappropriate behavior and sexual harassment and/or the assault allegations made.
I'd say it's something like "involving people without their consent" - e.g. farting on them.
Which includes forcing people to listen to tales of your sexual exploits.
So if we sit next to each other and I keep farting even though you don't like it, it's not harassment because it's not directed at you, but if I kept walking over to your area just to fart, that's harassment.
I would have thought the distinction would be obvious considering the overlap between HN readers and the socially awkward.
I wouldn't consider letting out a fart anymore inappropriate than excusing oneself to go to the bathroom, but doing either in a way that you know will disrupt and cause coworkers discomfort is inappropriate and harassing, not because of the act itself, but because of how you handle it.