[vanderZwan]

In all fairness, they're taking a more or less solved problem (feeds), so they don't really have to figure things out there, and they're porting this established solution to a very well-established technology (JSON), so also don't really have to figure stuff out in that sense either.

As far as scenarios where it's feasible to get the answer right the first time go, this is a reasonably realistic one.

EDIT: Also, if you scroll to the bottom of the page you can see they have let a whole bunch of people look at the spec before releasing it, so there has been at least some peer review.