scooterdude - 2:09 pm on Apr 3, 2012 (gmt 0)
I suggest that you re read the OP
First the OP has IMHO misinterpreted what was happening on his domain. Something happened, and then something happened a time after the first and this caused the OP to grasp at straws to understand.
This extract below was in the OP, it was a test, and it reflects the experience of many,
A couple of months ago, I did a test on a page, of a website I wasn't too concerned about. I chose a page, that had a first page rank for over a year, for it's target term.
I purchased 150 links, using 3 variations of anchor text, to see if it would harm the rankings. Within a week, the rankings were gone. They remained AWOL for 6 weeks. I eventually managed to get the links removed, and the rankings recently returned.