"Normalisation of deviance", in a Qantas setting, is that the failure of one engine in a four engine aircraft is "routine".
It is, right up until the second engine fails. That is the lesson Feynman tried to inculcate - just because a double engine failure hasn't happened yet does not mean that it gets to be a more progressively remote possibility just because it hasn't happened.
This is exactly equivalent as believing that just because Zero has not come up on your roulette wheel for the past Five hours, it is never going to come up.
To put it another way, Wirthless will be in the middle of explaining away a single engine failure as "not a serious safety issue" - when her mobile phone will ring...........