Having 50 goverments and a federal government, too...
It isn't easy to deal with 50 state governments, with their contradictory approaches to issues. Surprising things are legal in some states (Colorado Cannabis anyone?) and 10 years of jail in others. I am not long term fan of Google (at all), but doing business in all 50 states is very tricky.
Google didn't shut this guy down, they just closed of an avenue of prosecution. It really wouldn't be hard for him to attempt another perspective, but he might risk 'summary judgement' where MS ends up paying Google's legal expenses to defend the perspective.
In the American Legal System, virtually ANYTHING can be run in Civil courts, if all you want is money.