Pace
As for your last post, Flintstone already answered that. To quote his words of wisdom "Faced with doubts I believe that if any pilot showed due diligence and asked the right questions that would serve as a defence. However if a pilot felt they had to ask these questions on a regular basis I'd be wondering why they were still in that job."
I would add that the defence would quickly run out in the case of frequently having to ask.