diberry - 4:48 pm on Jul 12, 2012 (gmt 0)
This is really fascinating, and would be great news for all of us who have had content rewritten this way.
This may offer some confirmation of your theory: it's the first explanation I've read that explains to my satisfaction why one of my sites got hit by Penguin. I have some unique content (and it's been rewritten by others, just like yours), but I also write about some very common topics in my niche. Even though I always try to add *something* unique when writing about a common topic, I can totally see (in hindsight) an algo thinking my site overall wasn't unique enough.