aristotle - 1:31 am on Apr 21, 2012 (gmt 0)
Wouldn't it make more sense for Google to just do nothing until then? What you're suggesting is a "shoot first, ask questions later" approach.
Suspicions about the new backlinks could raise suspicions about the site itself. These suspicions would cause the rankings to drop. The rankings would recover when or if the suspicions are resolved. (Please keep in mind that I'm merely trying to speculate about possible causes.)