My point is that asking colleagues you trust is not enough to conclude that nothing of this sort happened. Maybe your colleagues weren't aware of what was going on?
A third party audit would probably be a better option. But I am sure Google knows how to handle these cases better.
In general, Google's internal culture is open and honest, but we also provide anonymous ways to give feedback within the company[1], so something like this would bubble up in a visible way.
[1] See for example the description of "Googlegeist," an annual survey where Google employees can give anonymous feedback, at http://www.slate.com/articles/technology/technology/2013/01/...