Guy had a dream that he drowned while crossing a certain bridge. R’ Chaim told him to ignore it, as we pasken that we don’t listen to dreams [please: the psak is not the point]. He repeatedly had the dream, and he kept giving him the same pask. He traveled over that bridge… and drowned! Family came to R’ Chaim, obviously upset. He told them: My psak was correct, and I would do the same even after having this knowledge!
How come you never repeat the stories where the shaila was asked what to do (when then Nazis came) and the psak was stay and you will be safe and then the Nazis came and sent the person to Auschwitz, and there are such stories.