The Intended Sense of “Fabricated”
When the hadith critics describe a report as mawḍūʿ (fabricated), they mean precisely what was stated above; it is not a declaration that the falsehood of that specific narration has been definitively proven and verified in its own right.
A Presumptive Judgement
The matter is conjectural: declaring a report fabricated or forged rests on a strong preponderance of probability, not on absolute, incontrovertible certainty, for even a habitual liar can on occasion tell the truth.
This consideration also answers the objection that identifying fabrication by the fabricator’s own confession is unreliable because he might be lying in that very admission. His truthfulness is accepted on the basis of predominant probability; were that not the case, it would never be lawful to execute a person who confesses to murder or to stone one who admits to adultery. Understand this well.
2 – Accusation of Lying
Accusing a narrator of lying applies when he is publicly known and spoken of as a liar in everyday matters, even though no lie has been established against him in prophetic narration.
The “Abandoned” Report (matrūk)
Under the same ruling falls any narration that contradicts principles of the Sacred Law that are necessarily and universally known.