What distinguishes the third view on narrators associated with non-disbelief-entailing innovation, which al-Nawawī calls “the fairest and soundest”?

Isnād as Part of Religion: Transmitter Competence, Fitnah, and Connected Transmission

• Accept every non-advocate without testing precision or reliability
• Accept advocates and non-advocates equally in every case of innovation
• Accept a non-advocate subject to the other conditions of reliability, but reject an active advocate
• Accept only one who considers lying permissible to defend his school