It can be seen as assault when you put your hands on another person without consent.
Not saying that is right or always the case, but it can be seen that way in a court.
That, allowing his guest to manhandle the maid, without raising any objection, was wrong. But all her other complaints shown here; he answered the door in his underwear, was very minor. Now, if he commonly answered the door nude, that would be a reasonable objection.
Maybe there’s more, unreasonable work hours or unsavory duties. Still, she could have quit at any time.
Duly noted!