I worked with a guy that operated like this, a technical expert in a very specialized domain. You'd ask him a question - he'd just stare at you in silence for 60s or more, and then give a very well-considered answer that you couldn't get from anyone else in the world.
His manager was used to this and sort of enjoyed the mystique of this monk-like expert that he was responsible for.
I once was in a meeting where we had to talk to the great expert on the phone. Let's just say his name was Otto. Of course, he worked remote quite often, in the days before Zoom. His manager calls him and puts the phone on speakerphone for the room to hear.
Manager: Otto, we need your input on .
Otto: Yes, I think that might work, but you'll run into .
Manager: Well, yes, we've considered that, but
A few minutes of reasonably normal conversation ensues between the assembled group and Otto. Then:
Manager: Well, I think then that this is a pretty good solution, as long as Otto agrees.
Manager looks around the table, clearly waiting for Otto's concurrence
People are starting to get uncomfortable. The manager makes a reassuring face. This is normal for those of us that work closely with the great expert, do not lose faith.
Manager briefly lets slip a concerned look, then quickly hides it
Manager: Um, Otto?
Otto: Oh, I thought I was waiting for you.