Planet13 - 3:55 am on Aug 12, 2011 (gmt 0)
Not likely, of course, but we don't have absolute proof it CANNOT occur... hence these recurring stories.
I agree that there is no hard evidence (I have been looking for it for a while now, since I am deathly afraid of an over optimization penalty - not that I am doing anything wrong, google, in case you happen to be reading this thread).
But I check into the warrior forums out there from time to time and you do see posts by people wondering why their sites were eviscerated after doing an xrummer blast.
It ain't really very conclusive. If they are the type of webmasters to take shortcuts by using xrummer, then probably they are taking lots of other shortcuts, too, and maybe it was the other shortcuts that caught up with them?