What is the ruling on declaring a specific person an innovator (mubtadi')?

For the issuance of rulings — such as declaring someone an innovator (tabdīʿ) — three conditions are stipulated: First: The Muslim remains upon his original state until the removal of that state is proven by a legal (Shar‘ī) دليل (evidence). Second: The Qur’an and Sunnah (definition) indicate that the action or statement necessitates the ruling. Third: The presence of conditions of knowledge and free choice and the absence of ta’wīl (misinterpretation) in the doer, and the absence of impediments such as ignorance, compulsion, and ta’wīl. As Shaykh al-Islam Ibn Taymiyyah explained, the establishment of the consequence of the warning (waʿīd) against a specific individual is conditioned upon the presence of the conditions and the absence of impediments. This applies to the torment of the Hereafter and the rulings of this world.