RTFA. It means: "kissing her and groping under her skirt" while the woman wakes up from blacking out.
They were kissing, and she claims she was too drunk to remember what happened before that. There is no evidence that she was passed out.
By itself, it proves nothing, however other women since reported similar stories.
When work colleagues are away from home, drinking heavily, and in one of the most romantic cities on Earth, things are bound to happen.
Some of them will be regretted. There is a simple old-fashioned way to avoid such problems: chaperones.
If the university does not want such encounters, ban the assistants from being alone with their bosses after hours or after drinking. If they stay in groups of two or more, they are safer. And it protects the professor from change-of-mind allegations.
A fact of life is that middle-aged men are extremely vulnerable to approaches from young attractive women. They need protecting, just as young employees need protection from those with power over them.