Re: How did the distributed bit actually work
With git, virtually everything that you do on it is completely offline and distributed, so most of what people do in git on a day to day basis isn't actually affected by whether github is online or not. Github is basically just a convenient place to store a definitive copy of the repository, and provides nice dev tools like pull requests. But as far as creating branches, writing code, and committing it goes - you do that totally independently of github. My point here is just that working locally is the normal state of affairs in git, rather than something that you would do in some kind of emergency situation.
Speaking from my experience, the sorts of things that are more likely to be affected by this are things like automated builds, deploying changes and code reviews (via github pull requests). But these issues aren't anything specific to git or github, since you'd have the same issue if any centralized repository went down, and you could easily sort it in an emergency by updating your build server or other tools to point at a copy of the repository (which every dev has on their machines by virtue of the way git works).