I don't really trust Isaacson to appreciate the significance of Jobs's remark, since he has proven himself to be technically incompetent, so it could be that Jobs had merely "nailed" the UI aspect of a television but hadn't yet worked out how to deal with the cable companies, content companies, bandwidth issue, etc. Who knows what the context is here?
So eager are you to rag on Isaacson's very good biography, you miss the big point here. We are not getting either details or context because Isaacson is deliberately suppressing them out of concern for Apple's trade "secrets," though that may not be exactly the right word.
Yes, Siracusa could list a dozen or more instances of Isaacson's non-mastery of the technical background, but it is naive to trash the book on that basis. It should have been the publisher's job to shepherd the project through some expert readers knowing that the author was weak on the tech. Maybe there wasn't time.
Siracusa rashly accuses the author of being lazy and uninterested rather than taking a more charitable and mature view that would have included the possibility of time constraints or editorial failures. To say that Jobs hired the wrong guy is arrogance. Gruber wisely backtracked a bit on the last 5by5, saying that it may have been strategic decision not to have a tech reporter nosing around Apple's business details.
The book is well worth reading for its insights into Jobs's penetrating native intelligence, and for the background it gives for his unique countercultural approach to the art of technical design. I know that's a vague statement, but it would take a while to flesh it out. Reading the book is a really good way to find out why it is Apple alone that has raised user experience to the level it has.
Update: Siracusa's second show on 5by5 about the book reveals that he just isn't seeing Isaacson's character study. He says the opportunity was squandered, we don't arrive at an awareness of Jobs's whole persona, and that's more important than the technical errors. Gruber is essentially in the same position; see his post today, where he shows how Malcolm Gladwell doesn't get Jobs either. So that's three who are blind to what I think Isaacson details very well. It seems to be a generational and (counter)cultural blindness on their part. Details available, if anyone's interested.
Update 2: At least Siracusa does say that everybody should read the book, but that's after doing his best to make everyone not want to. (This is an age of complainers who don't understand the effects of their complaints.) I would say it's the best biography we have of the most influential person of our time, and it's a great read. Don't miss it.