Not a lawyer, but will he have a case to sue for wrongful termination? I guess without seeing the employee contract and Code of Conduct, it is hard to say.
Unless the Google contract departs from boilerplate California employment contracts in ways highly disadvantageous to one of the largest, most legally savvy firms in the state, it is unlikely that Google needs a documented reason to fire anybody, so long as they aren't retaliating against them for concrete protected concerted actions in labor organization or retaliating against them for defending their rights as a pr…
Source: reviewed many regulatory actuarial filings, which are public record - mine were in Alaska but you might find the same by trawling thru https://fortress.wa.gov/oic/onlinefilingsearch/ or http://www.insurance.ca.gov/0250-insurers/0800-rate-filings/