Do you have a source that the Google hack was related to David Petraeus? This page doesn't mention it[1]. Does the timeline line up? Google was hacked in 2009[2]. The Petraeus stuff seems to have happened later.
Disclosure: I work at Google but have no internal knowledge about whether Petraeus was related to Operation Aurora.
[1] https://en.wikipedia.org/wiki/Petraeus_scandal
[2] https://en.wikipedia.org/wiki/Operation_Aurora