tedster - 12:55 am on Jul 3, 2012 (gmt 0)
Since you indicate that the back links are "optimized" I take this to mean that many of them did not occur naturally. Yes, this kind of "SEO" on backlinks absolutely can trigger a Penguin hit.
Even more, you might have found real-world evidence that a domain level 301 can transfer a Penguin penalty. People have been wondering about this, but so far yours is the first report of an actual case that sounds like it could be happening for real.
One case doesn't prove that the idea is true, but if others also add their similar experience to our discussion, then the idea will gain some strength.
The SE count the backlinks to blue-widgets.com as links to brand.com
Yes, no matter what the anchor text, a 301 makes the old back links "count" and send their strength for the new domain at almost full strength.