Does the admonisher who falls into the sin he forbids fall under the threat mentioned in the Hadith of the man who is thrown into the Fire, so his intestines gush forth, and how do we reconcile this threat with the obligation of enjoining good and forbidding evil?

The aforementioned Hadith (definition) describes the state of a man on the Day of Judgment who is cast into the Fire, and his intestines spill out, so he revolves with them as a donkey revolves around a millstone. The people of Hell gather around him, asking about the reason for his condition, and he replies that he used to enjoin good but did not do it himself, and he used to forbid evil but committed it himself. Although the Hadith is frightening, justice is not a prerequisite for one who enjoins good and forbids evil. The important thing is to perform this obligation even if the perpetrator is committing sins. The most complete is for one's words to match their deeds, to repent from their sins, and to be a good example, as Shu'aib (peace be upon him) did.