Blogg.se falls from the serp and penguin rises

The context:

The drop in visibility in the search results of Blogg.se is making swedish SEOs chat.
Blogg.se is a major blogging platform in Sweden and sunk in the SERPs making a couple ripples…

Ok, so is Blogg.se drop to be accounted to the Penguin’s update?

The short answer is:

NO

Well, clearly, the date don’t match:

Penguin Update: 24th of May
Fall of blogg.se: occured at least one week earlier (at least before the 19th)

blogg-se-vs-penguin-update

The explanation then? 🙂 some might have an idea.
Please email me if you know more about the causes but I am specially interested about the SEO consequences. Tack Tack.