«لَا يَحْصُلُ الْعِلْمُ بِصِدْقِ الْخَبَرِ مِنْهَا إِلَّا لِلْعَالِمِ بِالْحَدِيثِ الْمُتَبَحِّرِ فِيهِ»
The knowledge claimed from these particular corroborating circumstances is attained by the person deeply versed in hadith scholarship.
Such an expert understands narrator biographies and standing, hidden defects, comparative routes, and the methods of the critical imams as practical investigative disciplines, rather than isolated terms. The expert can recognize weight in indicators that a novice may not appreciate.
A beginner's inability to derive the conclusion does not prove that the expert's inference is impossible. Conversely, merely claiming to be an expert does not turn an uninvestigated assertion into certain knowledge.