With respect to 200 codes, I'd love to know the context.; I've been using a heavily modified jquery.tweet.js on my tweet feed on my site and it turns out that jQuery JSONP just drops anything that's not a 200 OK and puts a generalised error message in the console.

This does mean that when I've been testing/refreshing a lot and Twitter decides I've overrun my allowance (or if anything else goes wrong) I have to copy/paste the URI in the error message to find out what's happening for sure by getting the perfectly well formed JSON as raw text.

Sometimes, just sometimes, the apparent loopiness of an API can be there as a painful workaround to combat a shortcoming in something outside the creators' control.