I don’t take a position on this because I don’t know it but I think you’re (willfully?) misunderstanding the point. I don’t think all ethical problems can be legally defined. Something may be legal and wrong or illegal and not wrong. If she was indeed forced out for reporting sexual harassment, then what ethical responsibility does she still bear towards that company, regardless of what they ask her to sign as she leaves? The point isn’t that she’s right or wrong for sure, it’s that the problem is complex and legalities cannot account for all situations.