Ajax URLs and breaking the back button

I was reading a different thread (http://news.ycombinator.com/item?id=2161405), and when I followed it, I was taken through a series of redirects: https://github.com/documentcloud/backbone/issues#issue/201 -> https://github.com/documentcloud/backbone/issues/201/find -> https://github.com/documentcloud/backbone/issues/issue/201

The redirect form the URL with the named anchor redirects to the find URL via JavaScript's window.location property, and the find URL redirects to the final URL via a HTTP Location header.

When I reach the final page and click my back button, I'm taken to the named-anchor URL, which initiates the series of redirects, taking me back to the final page.

I know the named-anchor URLs are used so that Ajax interactions are reflected in the address bar, but it's annoying when they break expected behavior when used to link directly to a page. (In fairness, this doesn't appear to be a problem in Chrome; I'm using FF)

Twitter's also been bad about this recently. (Their URLs look like they're tailored for Google, to me: http://code.google.com/web/ajaxcrawling)

Companies should make sure their code doesn't end up trapping users in a redirect loop.

In GitHub's case, I believe using location.replace instead of window.location for the first redirect would solve the problem, although I'm not sure because I haven't tried it.

Is it possible to have these types of redirects without breaking the back button? If so, why are large sites making this mistake?