I've seen situations like that several times over several years. Google does not keep track of which version of an article is published first. They look at other factors. It is not hard to push a copied article ahead of the original article. It just takes a couple of good quality links.
I am not sure that I believe that a +1 click is going to move a dupe page ahead of the original. Cutts recently said that they are not using +1 clicks because they have not found them to be reliable. However, there could be something new going on with respect to +1.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin