At some point you need to draw a logical line, lest you arrive at Linus Torvalds inventing ChromeOS since he wrote the kernel for it way back in the early 1990s.
I have no knowledge of ChromeOS history other than what has been published here, but from my reading of these things it does seem pretty disingenuous for Jeff Nelson to claim to have 'invented the Chromebook'.
The wording "invented the Chromebook" is aggressive, especially for collaborative projects that collect many contributions and work on shared themes. But, journalistic accounts and promotional bioblurbs typically dumb things down, in exactly this way.
And, if at any point Google asserts that Nelson's '662 patent covers the Chromebook/ChromeOS or similar products from other companies, then it's a defensible statement, at the level of fuzzyness that's used in these contexts. It should be interpreted as, "invented [key enabling technology for] the Chromebook"... like when people talk about who "invented the iPod" or "invented AdSense".
I have no knowledge of ChromeOS history other than what has been published here, but from my reading of these things it does seem pretty disingenuous for Jeff Nelson to claim to have 'invented the Chromebook'.