Can a Hadith be cited as proof if it was narrated with a strong chain of transmission, or by trustworthy narrators?

The statement of the Hadith (definition) scholar, "Its narrators are trustworthy," or "Its chain of narration is strong," is not an authentication of the Hadith. The authenticity of a Hadith requires five conditions, and the presence of trustworthy narrators does not guarantee connection [of the chain] or freedom from anomaly (shadhūdh) and defect (illah). It is possible to use a Hadith as evidence even if it does not meet all conditions of authenticity. It may be used for corroboration, for seeking reassurance, or because it pertains to virtues. Furthermore, two weak [Hadith] together may become a proof.