can you be sure it was the Penguin #3 update Oct 5th 2012 or the page layout update a day or 2 later?
if it was that cute but smelly penguin then diversify the money anchor keywords , even throw in some “generic” keywords..
I have only been affected with a one page EMD with duplicate content from my other site in a non gaming niche (ranked top 5 for 3 keywords over 1 year with actual copied content )