Board's frequently resign en-masse
Umm... boards frequently resign en-masse. Especially, in the US. Board members can be sued for breach of fiduciary duty. If you are a public company, the company is expected to maintain a insurance policy for each board member to protect them from lawsuits. I was at a public company, that due to an administrative issue during transfer of the policy to a new company, was planning to operate without a policy for a week. The entire board was going to resign on the spot, because they wouldn't be members for even one day without insurance.
It is just too easy to start a lawsuit. If the board insurance goes away, or the expected liability of an "issue" exceeds the policy, the entire board is gone.
BTW, the board is liable if management embezzles the assets. The management too. And it is probably a criminal offense. I'm aware of this happening in any large US public company's. But again, in the US, CEOs and CFOs of public company's can and do go to jail for serious offenses.