A mudallis narrator may use wording that suggests direct reception even when an intermediary existed for a particular report. Thus his every “ʿan” cannot be presumed to establish audition. For a non-mudallis, critics consider contemporaneity, possible contact, and evidence of actual meeting according to their methodological standards.
Example: A known mudallis says “ʿan shaykhī.” The investigator looks for another route explicitly stating “I heard my teacher,” or credible evidence that the intermediary was absent in this specific report. General reliability alone is not necessarily conclusive.
This is not a claim that every mudallis is a liar. Tadlīs and deliberate fabrication are separate concepts; the technical issue is the history of acquiring this particular narration.