There has been some claims that an established posek who errs and permits a woman to remarry when she is still married to her first husband - should be treated with respect and not be banned. Even if he is told by many respected rabbis that he has erred and yet he refuses to retract his heter or even consider that it might be wrong. One of the sources brought was a Birchei Yosef (Y.D. 243:4) which seems to support such a claim.
ברכי יוסף יורה דעה סימן רמג
ד. מי שהוחזק להוראה וטעה אפילו בדבר ערוה, לא זו שאין מנדין אותו אלא אין מורידין אותו מגדולתו ואין מכלימים אותו. הרב מהרש"ל בים של שלמה יבמות פי"ו סימן י"א.
However the Birchei Yosef is simply a summary of the Yam Shel Shlomo. In the original source it says if the posek made a mistake concerning a halacha that bedieved is mutar he should not be shamed or put in nidoi. Clearly if he made a mistake which is prohibited even bedieved - he can be banned and embarrassed - and surely if he refuses to retract or even reconsider the matter despite world wide outrage.
The posek Rav Greenblat says he gave the correct halacha to the case presented to him. The problem is that the facts presented were lies. In response to that claim Rav Greenblatt said he takes no responsibility for the facts - only the halacha. Since he wasn't concerned with the truth of the facts, his psak stands independent of reality!
According to his logic the solution to all the aguna issues is simply to lie to a posek and get a heter for remarriage! We can stop wasting time with beis din or be concerned with a careful investigation of the facts - just have people manufacture fairy tales and have a posek issue his ruling of the fairy tale- totally independent of whether the facts are true. Truly an outrageous enterprise.
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Yam Shel Shlomo [1](Yevamos 15:11): A rabbi who is an established posek – even if he errs concerning prohibited sexual relationships such as permitting a wife to remarry if the husband disappears in a sea without visible end or similar issues which are valid only b’dieved – we do not put him in nido (ostracize) or shame him and he is still assumed to be a compentent posek.
Yevamos(121a):[[ Our Rabbis taught: If a man fell into water, whether it had [a visible] end24 or not, his wife is forbidden [to marry again];25 so R. Meir. But the Sages ruled: [If he fell into] water that has [a visible] end,24 his wife is permitted [to marry again],26 but [if into water] that has no [visible] end27 his wife is forbidden [to marry again].28 What is to be understood by has [a visible] end? Abaye replied: [An area all the boundaries of which] a person standing [on the edge] is able to see in all directions.29
Yevamos(121b):[[ A man once went about saying, Who of the family of Hasa is here? Hasa is drowned! [On hearing this] R. Nahman exclaimed, By God, the fish must have eaten Hasa up! Relying on R. Nahman's exclamation, Hasa's wife went and married again, and no objection was raised against her action.61 Said
R. Ashi: From this62 it may be inferred that the ruling of the Rabbis63
that [if a man had fallen into] water which had no [visible] end, his
wife is forbidden [to marry again] applies only ab initio, but if
someone had already married her, she is not to be taken away from him.
Yevamos(121a):[[ R.
Ashi said: The ruling of the Rabbis [that where a man has fallen into]
water which has no [visible] end his wife is forbidden [to marry again].
applies only to an ordinary person but not to a learned man for, should
he be rescued.39 the fact would become known.40 This, however, is not
correct; for there is no difference between an ordinary man and a
learned man. Ex post facto, the marriage41 is valid; ab initio, it is
forbidden.
Yevamos(121a):[[ Once a man was drowned in the swamp of Samki, and R. Shila permitted his wife to marry again. Said Rab to Samuel: Come, let us place him under the ban.30 Let us first, [the other replied,] send to [ask] him [for an explanation]. On their sending to him the enquiry: [If a man has fallen into] water which has no [visible] end. is his wife forbidden or permitted [to marry again]? he sent to them [in reply], His wife is forbidden And [they again enquired] is the swamp of Samki regarded as water that has [a visible] end or as water that has no [visible] end? It is, he sent them his reply, a water that has no [visible] end. Why then did the Master [they asked] act in such a manner?31 I was really mistaken, [he replied]; I was of the opinion that as the water was gathered and stationary it was to be regarded as "water which has [a visible] end", but the law is in fact not so; for owing to the prevailing waves it might well be assumed that the waves carried [the body] away.32 Samuel thereupon applied to Rab the Scriptural text, There shall no mischief befall the righteous,33 while Rab applied to Samuel the following text: But in the multitude of counsellors there is safety.34
Meiri[1](Yevamos
121a):[[
[1]
מאירי (יבמות קכא.): זה שביארנו בטבע במים
שאין להם סוף שאשתו אסורה דוקא שלא לינשא לכתחלה אבל אם נשאת לא תצא ואין גוערין בו
כלל וכמו שאמרו למטה מאן איכא בי חסא טבע חסא ואינסיבא איתתיה ולא אמרו לה ולא מידי
וכתבו גאוני ספרד דהוא הדין לכל שנפלו במקום סכנה העשוי למות שם אלא שאנו חוששין שיצא
אבל חכם שהורה לינשא לכתחלה מנדין אותו
[1] ים של שלמה - יבמות (טז:יא): ... שהרב המוחזק להוראה, אפילו טעה בדבר איסור ערוה, כגון שאם התיר מים שאין להם סוף, או כל כיוצא בזה, שבדיעבד מותר, אין מנדין אותו, ולא מכלימין אותו, והרי הוא בחזקת כשרות: