UOJ quotes the infamous letter written by Rabbi Elchonon Wasserman telling a student not to go to YU or HTC (Skokie), even though it would get him safely out of Europe:
"I received your letter, but unfortunately there is nothing I can do. The yeshivos in America which can bring talmidim from overseas are the yeshivah of Dr. Revel (YU) and [HTC in Chicago]. However, both are places of spiritual danger because they are run in a spirit of disloyalty to the Torah. Therefore, of what benefit would it be to escape [Europe] from physical danger to spiritual danger."…
UOJ notes that later in the letter, Rabbi Wasserman suggests the student contact Rabbi Shlomo Hymen at Yeshiva Torah Vodas who, Rabbi Wasserman writes, will help him. But then UOJ continues:
Rabbi Elchonon Wasserman was urged [by Rabbi Henkin] to bring over all of his students to Yeshiva Torah Vodaath and Rabbi Shlomo Hyman had agreed to step aside as the Rosh Hayeshiva and gladly have R' Elchonon take his place. Instead he went back to Europe where he was slaughtered along with his students . He is quoted in his "Kovetz Maamarim" as saying he intended himself and his students to be a "korbon" or a sacrifice, on behalf of American Jewry. So much for "daas Torah" and "gedolim infallibility".
Rabbis gave notoriously poor advice all during WW2; the above is only one example out of many rabbinic failures. From Hungarian hasidim to Chabad, from Litvaks to Galitzianers, rabbis failed. You can say this means God "hid" the truth from them, or you can say God never spoke to them in the first place. My money is on option number two.