YP - The problem is there is an increasing number of F/Os who have a "challenge everything" mentallity and don't buy into the Captain's authority full stop. There are also many situational examples which are not as clear cut as the "extreme emergency" where you have to follow the skippers lead. Our book ,for example, says before V1 we should reject for a predictive windshear alert. If this happens on a FLL runway just before V1 on a day where it is clear that it is spurious thedecision will be to continue. Not what the book says.... but the right thing to do. He/she is paid for judgement in the shade of grey areas.