I was puzzled briefly as to what JavaScript was doing there but thinking about it I've been doing some stuff with google maps and the API for that is mostly done with JavaScript objects.
Which makes very little sense, since JSON is a content type it's mostly orthogonal to using REST, *RPC or whatever. You can do REST with JSON, XML, custom binary or ad-hoc textual payloads, and you can do RPC with exactly the same.
Sure. Another way to interpret "JavaScript" is that it means using one of the various data-binding frameworks. But who knows, I didn't write the article.