tedster - 5:13 am on Feb 20, 2013 (gmt 0)
Could Google simply ignore those links?
In fact, they often do and they have been doing it for quite a while. I've seen many sites that never had an unnatural links notification and never showed any ranking problem, even though I can clearly see a major pile of very dicey backlinks.
What I can only guess at is why Google ignorse bad links in some cases but gets their back up in other situations.