Clicking the EN was one of the first things I tried when my forums suddenly decided I was multi-lingual. That action did not have an effect. Similarly, there is nothing in the html link that indicates it should be listing anything other than English.
I only see "http://www.swtor.com/community/showthread.php?t=598391" in my address bar.
That's...really weird. May I ask what browser you're using?