Maybe not technically, but he is a founder and I think he should take some responsibility. The wife's power came from his position in the company, and she was able to get away with that only because she was his wife. If my partner was coming into the office and intimidating employees at my company that is something we'd be having serious conversations about the minute I heard out about it. Of course I also like to think I wouldn't marry a psychopath, but that's neither here nor there, because if I left something like this for HR to deal with I'd feel like an impotent twit.

Within the context of the company, it's his responsibility as an founder and an executive. His wife (AFAIK) has no formal title or role at the company - all her power and influence is derived from his status as a founder/executive.

Yes, as a person with free will, his wife is ultimately responsible and "shouldn't" have done what she is alleged to have done. But in the context of corporate governance and law, he is responsible for allowing her to have privileges and access to the company that are quite unconventional.

Do you know this? Does she hold no stock? Do none of the finances have her signature?

Certainly not.

If the wife has a formal, executive role at the company, then that's a completely different matter. I'm just speculating based on the usual way of things - I could be completely wrong.