Haven't seen that happen once.

I think that when there are not explicitly stated attribution of liability for decisions that are at the core of a problem the general rule should be that the accountability should be proportional to the additional benefit that each agent or person receives for that decision. That rule is in the context that each agent is responsible to read information and communicate to others in the chain about the risks that decisions entails. The overall structure of an organization should have the goal of making such information about risk available for all agents in the chain in a way that the amount of information can be digested by the agents without much problems.

Not since scapegoating was invented.

Through what mechanism are they accountable for that if not corporate liability? If I pay a taxi driver to take me home from the airport, and he hurts someone by driving in a negligent way, I'm not accountable for delegating my driving decisions.