The fact he has never heard of FusionGPS (who has answered questions before Congress) indicates he either had Weisman run the entire thing, he is lying or he has lost his mind.
My bet is Weisman ran the entire investigation.
The most lucid, self righteous and strident moment of the entire Mueller testimony, was his defense of Weisman.
Weismann and Strock and McCabe probably ran the whole thing.