Circumstantial plus expecting the worst.

A company and founder with such an extensive list of publicly known misdeeds (starting with Facesmash), chances are that there are many skeletons left to uncover. Setting a precedent is no unknown course of action.

It's not much to go by, but I am a commenter on HN, not a lawyer and Occam's razor doesn't disagree either.

Because it is extremely unlikely she knew everything. Based on her book, she was last to learn quite a lot of ugly stuff she reports on - they told her only when they had to.

And she left long time ago. It is even more unlikely that the company magically became clean after her leaving.

Zuckerberg is the kind of Incel we have been warned about. Its how the Face Book started and it will be how it will end.