This is standard employee training presumably not just at Google, but at basically every company I've ever worked for.
The rule goes basically: if you don't think what you write would look good on the front page of the NYT, then don't put it in an e-mail.
Doesn't seem like a risk a competent retained counsel would want to take, in any case.
[1] http://www.acc.com/legalresources/quickcounsel/acpfihc.cfm
The only way to really get screwed over by these tests would be to instate a "no emailing the lawyers about corporate wrongdoing" policy (causing your employees to fail all three tests in the link).
Of course, the lawsuit alleges that Google did exactly that. I wonder if the courts will (imho correctly) strip a large percentage of their internal legal communications of attorney/client privilege.
Time to grab the popcorn.
NYT: To the dismay of their employees, Google insist on using slowALGO, possibly costing them X sum.