In practice, board bylaws and common sense mean that individuals recuse themselves as needed and don't do stupid shit.
A charity acting (due to the influence of a conflicted board member that doesn't recuse) contrary to its charitable mission in the interests of the conflicted board member or who they represent does something similar with regard to liability of the firm to various stakeholders with a legally-enforceable interest in the charity and its mission, but also is also a public civil violation that can lead to IRS sanctions against the firm up to and including monetary penalties and loss of tax exempt status on top of whatever private tort liability exists.