> That was their crime. They hid what settings they 
   > were really picking and specifically wrote software
   > to defeat an emissions test.

I actually agree with you on this. That said, I've heard people defend VW and presumably would GM as well with "The law says you must have this level of emissions when your car is tested. And that is exactly what they did, they made sure the car followed the law and emitted what was required of it to emit during the test." It completely side steps the intention of course, and I would certainly not sanction it as an excuse, but it nicely illustrates how sophistry and regulation are an odd match.