My Dad once sued microsoft because they had many "temporary" workers who did not get the full benefit of full time workers. These workers were labelled as contract workers however, he was able to win his case because at the end of the day, they were working full time for Microsoft. Not only that, they were often employed by microsoft for many years, even though the claim was generally that these employees were fulfilling a short term need.
He was able to get them damages for all sorts of things, including the fact that they were not entitled to store discounts while other employees were.
Even though he won, many companies including Microsoft still do the exact same thing with their employees. The only difference is they are trying to keep it under wraps so they don't get sued again.
Very likely, Google is trying to cover it's tracks in the same manner. They are probably less worried about racism than they are about this sort of permatemp law suit.
Let's face it, if they were doing something legal they wouldn't care if they were getting videotaped.
From my dad's firm's website: http://www.bs-s.com/cases/c-microsoft-vizcaino.html