Remember whatever happens, you really were right at the time

"Never apologise, never explain." Commonly attributed to Benjamin Disraeli

It is a natural law that top managers must take big decisions without evidence that they are right or wrong. It just as natural that post hoc evaluations will be unbalanced and unfair.

When a decision proves right, you must claim authorship not only of the decision but also of its upside consequences. This is your argument for being hugely rewarded, even though you took the decision without 'evidence' that it was right.

When a decision proves wrong, then you must argue you should not be punished or held accountable for the consequence, because there was no 'evidence' at the time that the decision was wrong. (E.g. nobody could foresee the fall in the housing market, that no Weapons of Mass Destruction would be found, etc.) Admit no errors of judgement.

Beforehand, stress the quality of your judgemental input. Afterwards, never say your judgement was wrong – you were right at the time given what was known then – it is just that events took an unforeseeable turn, to which you have now adapted yourself. Dismiss any suggestion that events could have been foreseen. Those who had sufficient judgement to foresee events, and advised you from the start to take the course you were eventually forced to take, did not have better judgement; they were wrong at the time, given what was known then. People like that always advise against any radical action anyway. They were right in this case, but only like stopped clocks are right twice a day.