Ilan is trying to prove something which is well known, even to rabbis. Historical examples of mistakes are on a much grander scale than what Ilan envisions. The classic example today of a grand Rabbinic error is the fact that rabbis encouraged their European flocks to remain in Europe and not make Aliyah, even as the Nazi storm was gathering. (The 30's were the best time for Aliyah to Israel, but the rabbis were anti-Zionists.) Most Rabbinic authorities were opposed to Zionism from the start. There are some counter examples, but the result was that religious Zionists played only a small part in the founding and development of the state of Israel. The situation has changed after 67, and now most rabbis are settler-oriented, participating in the greatest historical folly one can imagine (unless the Messiah shows uo soon...). One can go to earlier times, with the great sage Rabbi Akiva, considered the greatest of Mishnah authorities, supported the messianic claim of Bar-Kokhba. The result of that revolt (AD 132-135) for the presence of Jews in the Land of Israel was worse than the destruction of the Temple. Jerusalem was turned into a pagan city, Jews were forbidden to live within sight of Jerusalem, and Judea became generally depopulated. The problem with rabbis is that they are too much past oriented, and don?t look to the near future, only to the far future, the fictional messianic days.
Russia: U.S. plan to provide air cover for Syrian rebels undermines Damascus fight on ISIS (Reuters)
from the article: How great are the words of the sages?