I'm not a lawyer but I would like to think I have an understanding of the basics.
The default status for a piece of work is copyright, all rights reserved. So unless stated, you have no permission to copy it (outside fair use/dealing allowances). This does not require somebody to stick
Ⓒ Oli 2012 on a bit of work, nor does it require the author to register the work; it's all implicit.
In short copying the blog content onto the site (and thereby forcibly opening that content up to a CC-Wiki permission set - without permission) is nothing less than copyright infringement. It should not be done without the author's permission and in which case they should do the copying so there's absolute certainty about who is granting whom the license for that work.
I have rolled back the answer to it's original state.
Now, it's a crap answer as it was. The blog post isn't much better. I'd say just writing a new answer from scratch and downvoting the original would be the best solution.
For other cases, there are scenarios where links probably work out okay (bias alert: I've linked to my blog a couple of times) but one-liners that do nothing to answer the actual problem on the site, are poor.
You should probably consider them on the quality of the answer rather than automatically flagging because they contain a link to another website.