A 34 year old CEO asking a newly hired 23 year old college grad out on a date sounds like sexual harassment to me even if it was just a one time thing.
It certainly raises some interesting quid-pro-quo questions. Every sexual harassment training I've attended has mentioned this as very dangerous territory, but not explicitly sexual harassment.
If a CEO asked a much younger employee out and it made her so uncomfortable that she quit would you still say that it wasn't sexual harassment? Once is still too much. And for all we know Melinda might have felt compelled to say yes to avoid retaliation and only later accepted it.