I just listened to the recorded shiur and there’s quite a lot more to the discussion than just the conclusion presented here.
Joseph described some of the qualities of a rav muvhak in post #7 above. Rav Schachter adds quite a few more and also discusses criteria in selecting one’s rav, all relevant to this topic.
Clearly, we’re not discussing a case where some “posek” walks up to someone he’s never met and “paskens” that he should marry a woman about whom the “posek” also knows nothing about. Even Rav Schachter makes clear such behavior is not sanctioned by the Torah.
At the end of the day we do believe in Daas Torah. But, we also have an obligation to be judicious in whom we anoint with that title.