fathom - 2:04 pm on Apr 3, 2012 (gmt 0)
We are getting off topic here... the OP started with The return of competitors hurting your backlink profile?
There are actually 2 threads on this subject (1 in the supporters area).
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.
That in itself does not suggest a competitor did anything.
A larger issue "negative SEO" should not be argue here... it has nothing to do with this thread.
Coulda, woulda, shoulda is not part of my SEO repertoire. I don't use them to explain the unknown. If I cannot reproduce an event... it don't happen as you theorized.