Laker, I know of at least one case where the skipper refused to go into discretion after he warned SMNC about it. They forced him to go to TRV and promised him a short turn. You obviously can't refuse the first sector, because you are not flying into discretion yet. However he told them he would not fly the return if it meant he would have to go into discretion. Arriving at TRV, he told the ground staff that they needed to push at a certain time. Reply was "impossible". So he left the airplane and went with the crew to a hotel.
In this case, the skipper not only showed 'cojones', but he also took into account the 30 minutes after FDP towards his duty to calculate the minimum rest... :-)
Why you might never have heard of the story? The skipper never got called in because he was in his legal right to do what he did. The company keeps it quiet because they obviously doesn't want a lot of people to find out, because more guys might get the right idea...