Minority/Majority Scholarly Opinions And Ijma
There are three points: Understanding a directive of Deen Acting upon a directive of Deen Deducing ruling on a matter not mentioned in Quran and Sunnah, on the basis of the Quran and Sunnah All three involve human understanding which is subject to committing an error, not only at the individual level but also at the collective level. To follow the majority opinion in the matter of understanding is not obligated nor it guarantees that it is always correct. However, majority opinions are followed to avoid a dispute in something administrative matters, and this is another scenario. The hadith alluded to is about Dalalah and the whole ummah will not agree upon Dalalah. Dalalah does not mean mistake, it means going astray (gumrahi), that the whole ummah will not go astray. However, majority is not immune to committing a mistake in understanding and deducing a ruling.