Oh, sorry. Wire services often will update their stories multiple times, especially if the news is timely. That gives their subscribers (especially newspapers with early print deadlines) something to work with, and the promise of more later. It also can carry bragging rights, important in inter-newsroom rivalries, about being first to publish.

I've worked in newsrooms with direct AP feeds and I've seen as many as a dozen writethrus with major AP stories. On the internal feeds, at least, they're marked with version numbers and a terse explanation of what changed.

I'm mildly surprised that AP hasn't published a writethru on their own website. It's been over an hour. Perhaps they have on their direct feeds, not sure.

When writing to a cache simultaneously writes to the backing store [1].

[1] http://en.wikipedia.org/wiki/Cache_(computing)#Writing_polic...