I think that's usually the result of the previous page being a redirect, and the browser taking you back to the redirect page which then instantly, well, redirects you. I know this is a huge problem on mobile devices, often requiring you hit "back" twice quickly.
Not sure how smart browsers are about skipping redirect pages in the "back" history. If the page is a 301 I think the browser omits it from the history, but if they're doing less elegant redirects (such as, ugh, JS) I don't know that the browser will pick up on it.
I ran into this on ESPN during the NFL draft. Clicked some sort of analysis link, it was a 404. Tried to go back, the 404 page refreshed. I ran into several more 404 pages over the next 10 minutes or so, and eventually left for NFL.com.
Not sure how smart browsers are about skipping redirect pages in the "back" history. If the page is a 301 I think the browser omits it from the history, but if they're doing less elegant redirects (such as, ugh, JS) I don't know that the browser will pick up on it.