In his book "Studies in Maimonides and His Interpreters" (University of Scranton, Scranton and London: 2008), historian Marc Shapiro writes, referring to Maimonides' Mishneh Torah, that in traditional studies it is almost always assumed that "there is an answer for every perplexity". Shapiro writes (p. 3) that,
The possibility that Maimonides made a simple error, or that he overlooked a rabbinic passage - which entails bringing Maimonides down to the level of a mere mortal - is not an operating principle.
Shapiro, under the header "To Err Is Human", then goes on to list an extensive list of all kinds of errors committed by Maimonides in his writings. With this, Shapiro brought on himself the wrath of Asher Bentzion Buchman who went on to write an article titled "The Hagiographer's Review of Studies in Maimonides and His Interpreters" which was published in Hakirah journal. In the article, Buchman admits that the "hagiographic approach" is not limited to Maimonides, but also "extends to other chachmei hamesorah." Indeed, one of the major driving forces behind much of the Torah literature can be attributed to the traditional approach of assuming that a seeming error or contradiction is not the result of sloppiness or forgetfulness, but actually means something deep and profound.
However, learning any traditional source without this crucial assumption, will many times lead to the conclusion that the author in question was erring in one way or another. Of course, many times another traditional source might offer a plausible explanation, but other times it can be quite obvious that the author made a simple error. Here's one such example.
In BT Brakhot 37a it says as follows (edit: translation is from Soncino Talmud with minor changes of my own):
ואורז [ודוחן] לא מברכינן בורא מיני מזונות?! והתניא, "הביאו לפניו פת אורז ופת דוחן מברך עליו תחלה וסוף כמעשה קדרה", וגבי מעשה קדרה תניא, "בתחלה מברך עליו בורא מ"מ ולבסוף מברך עליו ברכה אחת מעין שלש"? כמעשה קדרה ולא כמעשה קדרה. כמעשה קדרה, דמברכין עליו תחלה וסוף. ולא כמעשה קדרה, דאילו במעשה קדרה בתחלה בורא מיני מזונות ולבסוף ברכה אחת מעין ג', ואילו הכא בתחלה מברך עליו שהכל נהיה בדברו ולבסוף בורא נפשות רבות וחסרונן על כל מה שברא.
[Previously, Rav and Samuel had said that on rice and millet one does not say the brakha of mezonot. Asks the gemara,] and over rice and millet do we not say, 'borei minei mezonot'?! Has it not been taught, "If one is served with rice bread or millet bread, he says blessings before and after it as for a cooked dish [of the five species]"; and with regard to cooked dishes, it has been taught, "He says before partaking, 'Shehakol niyeh bidvaro', and after it, he says one blessing which includes three [al hamikhya]? [answers the gemara:] It is on a par with cooked dishes in one way and not in another. It resembles cooked dishes in requiring a brakha before and after, and it differs from cooked dishes, because the blessing before these is 'borei minei mezonot' and the blessing after is the one which includes three, whereas in this case the blessing before is 'shehakol niyeh bidvaro', and the blessing after. 'borei nefashot rabot vehesronan etc.'
In short, Rav and Samuel say that on rice and millet one does not make the brakha of mezonot. The gemara asks from a baraita where it says that one makes on a bread of rice or millet the same brakha before and after as on a cooked dish, and on a cooked dish one makes mezonot and al hamihya. The gemara then ingeniously answers that it is only similar to a cooked dish with that it requires a brakha before and after eating it, but it is not similar to a cooked dish with regard to the brakha it requires. Later, the gemara asks a question from another baraita and concludes that the halakha is not according to Rav and Samuel and on rice one makes the brakhot of mezonot and al hamihya.
But R. Asher b. Yehiel, also known as the Rosh, writes (ad. loc 8) as follows:
על אורז, אם אפאו ועשה ממנו פת או שבשלו ועשאו כעין דייסא, מברכין עליו תחלה בורא מיני מזונות ... ולאחריו בנ"ר ... והא דתניא לעיל, "הביאו לפניו פת אורז ופת דוחן מברך עליו כמעשה קדירה"? אברכה ראשונה קאי, שמברכין עליו בורא מיני מזונות.
On rice, if he cooked it ... he makes the brakha beforehand of borei minei mezonot ... and afterwards borei nefashot rabot. ... And regarding what was [quoted from a baraita], "If one is served with rice bread or millet bread, he says brakhot as for a cooked dish", this only refers to the brakha beforehand, in that he makes on it borei minei mezonot.
Alas, the only way it's possible to sustain the Rosh's explanation of the baraita is by ignoring the words "תחלה וסוף" - "before and after it". Otherwise, how do we explain the meaning of those words? the words can't as the original explanation the gemara gave (that it has the same brakha before and after as a cooked dish), because the Rosh posits that the comparison to a cooked dish only applies to the brakha beforehand. But it also can't mean the gemara's second explanation (that one makes a brakha on it before and after eating it, just like one does on a cooked dish) because according to the Rosh, rice is compared to a cooked dish because it has the same brakha beforehand!
There are only two ways to explain the Rosh. Either he had an alternate version that left out the words תחלה וסוף, or that he (mis)quoted from memory. In this case, I think it's clear that the Rosh didn't have an alternate version, since a few lines after the above quote, the Rosh quotes the baraita again, and this time he includes the words omitted earlier:
וכן משמע ההוא דלעיל הביאו לפניו פת אורז ופת דוחן מברכין עליו תחלה וסוף כמעשה קדירה.