Are you suggesting that employment law shouldn't apply to management? That's the only way someone could be 'brought to account' for an error only visible in hindsight but fully supported at the time...
Fair point, I'd expect some sort of action to be taken on a bunch of people or individuals that wiped out 100's of millions of pounds in profit that the rest of the workforce have to suffer because of.
I wouldn't then expect that indivdual to get 1.2 million as a bonus payment for being a **** up.