HaGaon HaRav Moshe Schapiro ztz"l held very strongly that Rebbe Akiva and the Chachomim did not make a mistake in thinking that Bar Kochba was Moshiach. CHAS VI-SHALOM!! IT CAN'T BE!! He is even quoted as saying that this is readily apparent to "anyone who knows how to read". The reality is that he was on the way to being Moshiach but it didn't work out. The Rambam compares this to the destruction of the Beis Hamikdash. So there was a real chance that he was to be the Anointed One, King Messiah but because of sins it didn't pan out. Here is what he said as quoted in the Afikei Mayim on Shavuos:
One may note that many thought that Rebbe Akiva and the Chachomim were mistaken such as Rebbe Yonatan Ben Torta who said [Yerushalmi Taanis 4/5] when Rebbe Akiva called Bar Kochba Moshiach:
"עקיבא, יעלו עשבים בלחייך (=תקבר באדמה ועשבים יצמחו בה) ועדיין בן דוד לא יבא"
In addition, no less a personage than Rav Meir Simcha, the author of the Ohr Sameach and Meshech Chochma wrote [Devarim 8,10] מלכות בר כוכבא שגדולי עולם היו מוטעים בו. [As an interesting aside - In the Meshech Chochma on Eicha, he writes that the Chchomim thought that Rebbe Akiva laughed when he saw a fox come out of the Kodesh Kodashim [Makos 24] because he thought that Moshiach [i.e. Bar Kochba] was already here, עיי"ש on the pasuk על הר ציון ששמם.]
Moreover, how are we to understand the concept of פר העלם דבר של ציבור and for example the first Mishna in Horiyos which states הורו בי"ד לעבור על אחת מכל מצות האמורות התורה and Rashi says that they paskened that it is permitted to eat chelev or drink blood [!!].
I am not saying that Rebbe Akiva and the Chachomim were mistaken. I will leave that for greater people to discuss. I am just questioning if we must believe that anyone is infallible.
This in no way lessens our respect and reverence for our leaders and tzadikim or our obligation to follow their directives.
Hopefully more on that in future posts ברצות ה' דרכינו.