To "Cite" an article does not explicitly mean you are linking to it. I could for example reference Google+ Authorship and simply because the two words "Google" and "Authorship" appear together it's clear this is the subject I am referring to. However, this is not citing a specific article or author.
I'll use the example of the "Skills Exchange Network" as an example for now. I won't link to the website or even reference the URL in plain text. If cocitation exists and Google is indeed using it as a ranking factor then at some point in the near future this article should appear as a link back to the "Skills Exchange Network".
History of Cocitation
I've been designing websites for a few years now and I recall Google using a system similar to this in the early 1990s to identify spammy websites or websites that were untrustworthy.
Google have clearly moved on a long way since then and perhaps this is the next evolution in semantic search...?
In short: cocitation is simply a theory, a "Work In Progress" for us and I for one will be keeping a close eye on Google and what happens over the coming months regarding Google+ Authorship and cocitation in particular