The pause may have been rehearsed, though.
An anecdote from the book "Steve Jobs in Exile" I just read: at the beginning of one product announcement, Jobs told the audience that he was a little nervous, but his coworkers said that he was never nervous for keynotes. It was pure manipulation.
I wouldn't count it as manipulation, it can be a good way to connect/relate with audience beforehand. Similar to making a joke?
I'm sure the pause is something he rehearsed at some point, but I've watched a few of his Q&As where he's done it. If I recall, he was even doing it in the 90s (the Q&A I'm thinking of is the one where he picks up a chair and pretends to use it as a shield). So while I'm sure it was something he originally rehearsed, it undoubtedly just became a habit of his over time.
One might say showmanship.
Obviously lying to people you know is generally unhealthy but when you are putting on a performance to an audience I don’t judge so harshly. Of course I imagine he did both.
He really did feel comfortable with sitting in the silences though. His '97 response to a tough question springs to mind: https://www.youtube.com/watch?v=oeqPrUmVz-o
He doesn't actually answer the question until over 25 seconds have passed!
He takes a sip of water, sits in silence, the crowd starts heckling. Jobs gives a small quip to buy time. Sits in silence again. It's an eternity on stage.