The "Back" button works for me after I've cluck the link ... I wonder what you're seeing that I'm not.

Ahh, I'm on firefox - wonder why its only there?

Oh wait, I think that's even worse. This is the case for all google sites, if you use firefox, back button is disabled. Maybe this is to worsen the user experience for Firefox and encourage use of Chrome?

I'm also using Firefox. No addons, running on Ubuntu. I click on the link, read the article, click the "Back" button, and everything works as I expect.

Maybe you have some scripts or addons.

Wow, ok, very interesting. It must be something about my particular environment (Also on Ubuntu) that it only affects google sites.

this does not occur for me (Chrome, Windows)