I'd imagine in those negotiations there are agreements that everyone has to basically be tight lipped even after the deal falls apart. On the flip side, if Google had said too much it might make other business nervous to enter into negotiations with them in the future.
Someone wasn't so tight lipped that the word didn't get out that they offered $6 billion for the company.
If that wasn't true, someone in Google did have obligation to deny it - denying it off record with no further comment would hardly have been saying a lot.
