Does proof that two reliable narrators once met establish the full soundness of every report between them?

Muʿanʿan Transmission: Possible Meeting, Evidence of Hearing, and Continuity

• Yes; no scrutiny of the text or routes remains necessary
• No; it informs one continuity question while other criteria remain
• Only if the chain contains exactly four transmitters
• Yes; a known encounter makes the report mutawātir