You raise a difficult issue - how you would honestly resolve it. On one hand, CSOs cannot be personally liable for every hack. On the other, they shouldn't be given a pass on everything either.
So how does one draw the lines between bad luck, reasonable security problems, everyday poor performance, civil liability, and criminal negligence?
> A random engineer could make a mistake that gets hackers a step closer
That could be prevented, to a large extent, with much tighter controls. Of course, those controls would greatly increases the cost of operations and other things.
Is it possible we're all accustomed to the wrong model, that our standard of IT security is like the standard of car safety in the early auto industry (and maybe until the 1970s) - far too lenient? Maybe we should be facing the potential fact that the normal cost of IT should include those controls and other security expenses.