The Hajaawirah Haddaadiyyah have fought a great battle to exonerate and defend al-Hajuri in the issue of accusing Uthmaan (radiallaahu anhu) of instituting bid'ah into the religion, and they have a variety of ways in this battle. From these ways is to make use of the statement of Ibn Umar (radiyallaahu anhu) that is reported by Ibn Abee Shaybah in his Musannaf:
الأذان الأول يوم الجمعة بدعة
The first adhaan on the day of Jumu'ah is an innovation.
Thinking that this is rejection from Abdullaah Ibn Umar of the action of Uthmaan (radiyallaahu anhu), whereas in reality - if we accept for argument's sake that it is authentic - it is a statement similar to the father of Abdullah bin Umar which is Umar bin al-Khattaab (نعمة البدعة هذه), "What an excellent innovation this is" in relation to the Taraaweeh prayer in Ramadaan. For the use of the word (bid'ah) here is with its linguisting meaning, not shar'iyy, legislative meaning.
Ibn Taymiyyah said in Minhaj al-Sunnah (6/292)
And what was done by Uthmaan of (adding) the first call of prayer, the people were agreed upon it after him: The people of the four madhhabs and other than them, just as they agreed upon what Umar had also instituted of gathering the people behind a single Imaam in Ramadhaan.
And he also said (21/319):
So whatever the rightly-guided Khulafaa instituted is not a legislatively (defined) innovation that is prohibited against, even if it is described as "innovation" linguistically, due to it having been initiated. Just as Umar said, "What an excellent innovation this is..."
This shows the correct understanding of the saying of Ibn Umar, he is simply describing the adhaan instituted by Uthmaan (radiyallaahu anhu) with the linguistic meaning of bid'ah, meaning it was not present before and is something new.
The same is said by Shaykh Ibn Baaz (here) when he was asked specifically about the adhaan of Uthmaan:
ولهذا أقره الصحابة - يعني عثمان - في زمانه وعمله المسلمون من بعده ... وهكذا ما فعله عمر رضي الله عنه من جمع الناس على إمام واحد في التراويح في رمضان
And for this reason, the Companions accepted [the instituted adhaan) from him - meaning Uthmaan - in his time, and the Muslims acted upon it after him... and likewise what Umar (radiallaahu anhu) did of gathering the people behind a single Imaam in the Taraweeh prayer in Ramadaan.
So the statement of Ibn Umar that the adhaan of Uthmaan (radiyallaahu anhu) was bid'ah is agreed upon by everyone, for it is a bid'ah in the linguistic sense of the word. And had it been a bid'ah in the legislative sense of the word it would mean all the Companions affirmed Uthmaan upon bid'ah and dalaalah and mukhaalafah (opposition) to the Messenger (sallallaahu alayhi wasallam) - see Shaykh Ibn al-Uthaymeen's speech (here). This is how a person would view the situation in reality. And in any case, if any other Sahabee differed, the matter would return back to the Khulafaa and what they instituted as commanded by the Messenger (sallallaahu alayhi wasallam). Ibn Taymiyyah said in al-Majmu' (32/347)
For when others oppose the rightly-guided Khulafaa (in a matter) it is their saying that is superior because the Prophet (sallallaahu alayhi wasallam) said, "You must follow my Sunnah and the Sunnah of the rightly-guided khulafaa after me. Hold fast to it and bite onto it with the molars. And beware of the newly-invented matters, for every innovation is misguidance."
Now a person might ask: What about other scholars who might have held the same view of the second adhaan being in opposition to the Sunnah of the Messenger (sallallaahu alayhi wasallam), are they misguided and deviant as well? The answer to that question is that those Scholars who held this view, they are excused because the matter was not taken up with them and exhaustively debated such that their error became apparent to them. Further, unlike al-Hajuri, the Companions were safe from the tongues of those scholars, for we see al-Hajuri having a range of other revilements upon the Sahaabah, such as accusing them of participating in the murder of Uthmaan (radiallaahu anhu), innovating Irjaa', being punished twice for two disobediences (see here) and other such affairs. Thus the persistence of al-Hajuri and his followers in this matter, after the evidence clearly exonerates Uthmaan (radiallaahu anhu), then it is a sign of following desires. As for their use of the positions of certain scholars like Shaykh al-Albaanee, that is not for them, but it is against and that will be covered shortly.
Refer to the article (صد البغي والعدوان عن الخليفة الراشد عثمان) which has been use for this article for further details on this matter.