Oh my. He was a Posek but not a Rav?? Are you serious? What he is saying is that when faced with a choice of who to follow, he’d follow the one who actually had a position to Pasken, and who’s writings are based on real world P’sakim. The reason we Pasken like Shmuel by Dinim is because he had experience. We Pasken like Rav in Issurim because he experience in that. Even in their own times Shmuel would tell you that the Halacha is like Rav, although he actually firmly held his own point.
