From the SEW article:
The link issue has been the same for almost every Google update over the past five years. Lots of quality links appears to overcome the threat of penalties.
The threshold isn’t the same for each domain. Links seem to cause some difference.
Wow! This was not a simple test.
We ended up with 50 separate domains. None of them could be linked to each other through signals like ownership, hosting, Google accounts, or link partners.
It is also interesting that they observed that a page was either hit by Panda or it was not. There weren't any "degrees" of penalty applied.
"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