I think what's confusing some people is a bogus idea that the
current iPad design came first. Obviously it did not.
Even Jobs didn't say that today's actual iPad design came first.
He said that a glass faced prototype touch tablet and its UI gave him the idea for the iPhone touch screen. So the prototype begat the iPhone which begat the iPad.
That makes sense. Everyone was doing tablets. And we know from multiple history articles that mobile OSX did not exist until the port was begun for the iPhone in early 2006.
Their scrolling story has slightly changed, though. For example, back in early 2007 the WSJ interviewed Apple insiders and
got this version of events which claimed flick-scrolling came from an iPhone engineer:
At one point, Mr. Jobs got a call from one of the iPhone engineers with an idea: Why not allow iPhone users to navigate through both song collections and contacts stored on the device by simply flicking their fingers up and down across the surface of the touch-screen? The engineer gave Mr. Jobs a demonstration of the technology, and the Apple chief executive signed off on it immediately, according to a person familiar with the process.
Actually, it could've come from multiple engineers. The humorous thing about flick-scrolling to anyone who's done a touch UI since the 1980s (me, for example), is that it's a common accidental discovery, initially caused by hardware being unable to keep up with constant scrolling commands. In other words, you write code to scroll with a finger, but it keeps going after you let up. Then you get the "aha!" moment when you realize the extra lag could be useful. I think this has happened to everyone coding touch.
(Apple's huge UI goof was to throw out the baby with the bathwater, and totally remove most scrollbars in favor of flick scrolling. Sucks for long webpages, and really sucks for long documents. Both methods should be available.)