In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Dr Muhammad Bin Haadi [may Allaah rectify his affair] made Tabdee without evidence. This is why Al-Allaamah Rabee Bin Haadi Al-Madkhali [may Allaah protect him] sternly demanded evidence from Dr Muhammad Bin Haadi for his oppressive judgements, but received no reply. See here: Reminder: Shaykh Rabiʿ’s request for Shaykh Muḥammad bin Hādī to justify his tabdīʿ of Salafī students and shaykhs and to explicitly name the major scholars he accused of being “affected” and “destroyed” by the “Ṣaʿāfiqah” – one month, no answer: https://twitter.com/abuiyaadsp/status/1018974451269033986?lang=en-GB
Likewise, vile Usaamah made Tabdee of us without any proof and even extended the affair to a far greater extent. He stated that amongst us are those hiding the doctrine of the Khawaarij, that we are Haddaadees, ahlul bidah, pretenders in our beliefs as Salafiyyoon, hizbiyyoon etc. He has not recanted, rather even some of the ignorant Musaafiqah are parroting his satanic verdict.
This was our response to him in brief:
 Usaamah Ibn Ataayaa – [The Pottymouth Vile Hater] – Roaming The Dangerous Borders of Conjecture and Vain Desires By Passing Judgements Without An Atom’s Weight of Proof!
 Usaamah Ibn Ataayaa’s – [The Pottymouth Vile Hater] – Verdict of Hizbiyyah Against Us Based on Guessing and Aggravated (Compounded) Ignorance or Vain Desires?!
The Consequences of His False Judgement
What are some of the consequences of Tabdee and how is a Mubtadi viewed and dealt with?! The following Aayaat of the Qur’aan and statements of the scholars will give you a brief introduction to the affair. After reading, then ponder regarding the crime of one who passes the judgement of Tabdee based on haste, anger, conjecture, oppression and vain desires. Ahmad Ibn Sinaan Al-Qattaan (rahimahullaah) said: There is no Mubtadi in the world except that he hates ahlul hadeeth, and when a man innovates the sweetness of hadeeth is removed from his heart [Aqeedatus Salaf 102]
Ibnul Jawzi said, Abul Wafaa Ibn Aqeel Al-Faqee said, our Shaikh Abul Fadl Al-Hamdaani said, “The innovators (in) Islam and the fabricators of Hadeeth are worse than the Mulhiddoon [i.e. the heretics (Ref A)], because the heretics aim to corrupt Islam from the outside, whilst these [people] want to corrupt it from within. They [i.e. the innovators and the fabricators of hadeeth] are similar to the people of a country who try to corrupt its state of affairs and the heretics are similar to those who lay a siege from the outside; so the ones from within [i.e. the innovators and fabricators of hadeeth] open the fortress. Therefore, they are more harmful to Islam than those who do not [attribute] themselves to it outwardly”. [Quoted by Shaikh Rabee (may Allaah preserve him) in his Book titled: Al-Mahajjah Al-Baydaa Fee Himaayati As-Sunnati Al-Gharraa’i Min Zallaati Alhlil Akh’taa Wa Zayghi Ahlil Ahwaa’ page: 47]
Allaah [The Most High] said: [ أَفَمَن زُيِّنَ لَهُ سُوءُ عَمَلِهِ فَرَآهُ حَسَنًا – Is he, then, to whom the evil of his deeds made fair seeming, so that he considers it as good (equal to one who is rightly guided)?] [Surah Faatir; Ayah 8] Sa’eed Bin Jubair [rahimahullaah] said, “This was revealed concerning the people of bidah and desires”. [Tafseer Al-Baghawi 3/689]
Shaikhul Islaam Ibn Taymiyyah [may Allaah have mercy upon him] said: The pious predecessors named Ahlul Bidah Wal Furqah [i.e the people of Bidah and Splitting]- those who oppose the Book and the Sunnah- ahlul ahwaa [the people of desires], because of the fact that they accept what they love and reject what they hate based on their desires without guidance from Allaah. [An Excerpt from Majmoo Al-Fataawaa 4/189-190]
Allaah [The Most High] said: [وَلَا تَرۡكَنُوٓاْ إِلَى ٱلَّذِينَ ظَلَمُواْ فَتَمَسَّكُمُ ٱلنَّارُ -And incline not toward those who do wrong, lest the Fire should touch you]. [Surah Hud: Ayah 113]
Al-Allaamah Rabee Bin Haadi [may Allaah protect him] said, “The word [ظلم –wrong] in [this ayah] can [mean] disbelief; it can mean bidah and it can be [فسوق i.e. sinful, immoral behaviour], because (ظلم) can be applicable to all [i.e. in different contexts]. Therefore, we refrain from inclining towards the evil doers, the people of bidah, the Kuffaar, the Ilmaaniyyoon and other than them. And we protect ourselves, our Aqeedah, the Eemaan and sound religion which Allaah has bestowed on us”. [Source: An Excerpt from (الذريعة إلى بيان مقاصد كتاب الشريعة ) Vol 1 pages 192-193. Slightly paraphrased]
Ibn Abbaas [may Allaah be pleased with him and his father] said, “Do not sit with the people of desires; for indeed it causes sickness of the heart”. [Reported by Imaam Al-Aajuree in Ash-Sharee-ah: 1/453]
Imaam Ahmad [may Allaah have mercy upon him] said, “Beware of writing down (knowledge) from one of the people of desires-be it a little or a lot”. [Siyar 11/231]
Sa’eed Ibn Amr Al-Bardha’ee [may Allaah have mercy upon him] said, “I witnessed when Abu Zur’ah was asked about Haarith Al-Muhaasibee and his books; so he said to the questioner: ‘Beware of these books; they are books of bidah and misguidance'”. [Al-Meezaan 2/165]
Sallaam Ibn Abee Mutee [may Allaah have mercy upon him] said, “A man from the people of desires said to Ayyoub As-Sakhtiyaanee, ‘O Abaa-Bakr! I want to ask you about some statement’, so Ayyoub walked away and started gesturing with his finger, saying, ‘Not even half a statement'”. [Reported by Imaam Al-Aajuree in Ash-Sharee-ah 1/440]
We Call Usaamah to Mubaahalah
Al-Haafidh Ibn Hajr [rahimahullaah] said, “There is a benefit in the story of the people of Najraan, and in it is that Mubaahalah is legislated against the opposer when he persists upon [falsehood] after the proofs have been manifested. Indeed, Ibn Abbaas [radiyallaahu-anhumaa] did call to it, then Al-Awzaa’ee [rahimahullaah] and some of the scholars. And that which is well known from experience is that the affair of one who performs Mubaahalah – whilst he is one upon falsehood – does not extend beyond the year of the Mubaahalah. This occurred between me and a person who was fanatically supporting some of the heretics and after two months he could not stand up”. 
Shaikh Albaanee [rahimahullaah] was asked about the ruling on MUBAAHALAH in relation to worldly matters: Question: The hadith regarding the Najran delegation is well known when they came to the Messenger of Allaah [peace and blessings of Allaah be upon him], and then Allaah revealed:
فَمَنۡ حَآجَّكَ فِيهِ مِنۢ بَعۡدِ مَا جَآءَكَ مِنَ ٱلۡعِلۡمِ فَقُلۡ تَعَالَوۡاْ نَدۡعُ أَبۡنَآءَنَا وَأَبۡنَآءَكُمۡ وَنِسَآءَنَا وَنِسَآءَكُمۡ وَأَنفُسَنَا وَأَنفُسَكُمۡ ثُمَّ نَبۡتَہِلۡ فَنَجۡعَل لَّعۡنَتَ ٱللَّهِ عَلَى ٱلۡڪَـٰذِبِينَ
Then whoever disputes with you concerning him [‘Iesa (Jesus)] after (all this) knowledge that has come to you, [i.e. ‘Iesa (Jesus)] being a slave of Allah, and having no share in Divinity) say: (O Muhammad) “Come, let us call our sons and your sons, our women and your women, ourselves and yourselves – then we pray and invoke (sincerely) the Curse of Allah upon those who lie.” [Surah Aal Imraan. Aayah 61]
So he called them to MUBAAHALAH, but they refused. It is well known to us that MUBAAHALAH is not to be done except in issues related to Aqeedah, but some people amongst the Muslims suggest this ruling in worldly affairs between him and his Muslim brother; meaning, if my Muslim brother owes me money but denies it, then would it be permissible to suggest this ruling between me and my Muslim brother?
Answer: May Allaah bless you. The answer to this question is that it is not permissible to suggest this in such a situation or suggest this Sharee’ah ruling in relation to material issues due to two reasons: Firstly, because this story is related to issues of Aqeedah as you have stated today. Secondly, as for the material issues, then Islaam has legislated a system and principle for it. He [i.e. the Prophet (peace and blessings of Allaah be upon him)] said, “The burden of proof is on the claimant and an oath is a duty upon the one who denies the claim”. So, there is no room for Mubaahalah in this affair, which Allaah [The Mighty and Majestic] legislated in that affair between His Messenger [peace and blessing of Allaah be upon him] and those Christians of the Najran who denied true Islamic Monotheism and persisted on the Trinity. So, this affair is not suggested in another issue besides this because neither is there a narration of the pious predecessors nor a hadeeth regarding it. However, if it must be done, then it can be suggested when two groups of Muslims differ in some ideas or Aqeedah- for example between the Mutazilah and Ahlus Sunnah. It is possible that if some Mu’tazilee is haughty after discussion and after evidences have been presented, then the Sunnee seeks Mubaahalah from him – that may the curse of Allaah be upon the liars. Therefore, it is possible to suggest this in such an affair.  But as for the question with regards to suggesting this affair in issues related to material dispute, then this is not permissible. [An Excerpt from ‘Silsilah Al-Hudaa Wan-Noor 703’. Slightly paraphrased]
Usaamah has persisted upon his error and satanic judgement to the extent that even some of the ignorant people are repeating the same judgement against us. All the affairs he has accused us of are related to Creed. We say to him exactly that which Shaikh Abu Iyaad said to lamont Battle: “So I say: Lamont Battle is an ahmaq (fool) and his hamaaqah (foolishness) becomes clearer and clearer to everyone by the day. I will not stoop so low so as to ask him to recant and apologise to me because, judging by his behaviour so far, he does not have that sense of justice and it appears that Shaytaan has gained mastery over his nafs in this issue. So all I will say is that may Allaah’s curse be upon the liar. Whoever is lying, may Allaah’s curse be upon the liar. And if he is truthful, then let him call Allaah to witness and invoke the curse of Allaah upon the liar. I am free and innocent of his evil slander and I have no concern whatsoever with his personal or private affairs”. 
Therefore, we also say to Usaamah: Usaamah is an ahmaq (fool) and his hamaaqah (foolishness) becomes clearer and clearer to everyone by the day. We will not stoop so low so as to ask him to recant and apologise to us because, judging by his behaviour so far, he does not have that sense of justice and it appears that Shaytaan has gained mastery over his nafs in this issue. So all we will say is that may Allaah’s curse be upon the liar. Whoever is lying, may Allaah’s curse be upon the liar. And if he is truthful, then let him call Allaah to witness and invoke the curse of Allaah upon the liar. We are free and innocent of his evil slander that we are ahlul bidah, haddaadees, pretenders in our beliefs as Salafiyyoon, hizbiyyoon, and that amongst us are hidden khawaarij etc”.
[Ref 1: An Excerpt from ‘Fat-hul Baari’ 12/195. Slightly paraphrased]
[Ref 2: We do not enter into debate with anyone, rather leave it to those who are firmly grounded in knowledge.
Read: https://www.abukhadeejah.com/shaikh-rabee-decisive-words-regarding-permissible-and-forbidden-debating-in-explanation-of-imam-al-barbaharee-d-328h/ https://soundcloud.com/masjidassunnahaston/sets/principles-of-debates
[Ref 3: http://www.manhaj.com/manhaj/articles/plnox-lamont-battle-resentful-hater-who-accuses-ahl-al-sunnah-of-cultism-30-mistakes-in-3-minutes.cfm ]