Has Google released any statement beyond the one that said "We were mortified to learn that a team of people..."?
I'm overly curious on the results from Google's investigation. I can see the connection with Mocality being mentioned, but vandalizing seems odd.
I would venture that this is coincidental.
Pick any branch office of a large enterprise or government and run a search for the IPs they use to access the internet. You'll find vandalism on Wikipedia, ancient guestbook messages, mailing list postings, etc.
I'm certainly not a Google apologist, but this just seems fishy.