OP: Yes, you can lose control even with the VDC on and here's why. The rotation of the tires in relation to each other and at various states of the input sensors determines when certain safety systems are activated. I am not aware of the 370Z containing any sort of inertial measurement instruments so we can throw that out unless someone has data to support such a system.
Theoretically the car's safety systems will not engage if all four tires are rotating at the same speed and you are not pushing the brakes. This situation can happen if you are hydroplaning, sliding on ice or oil, or possibly going airborne. I personally have had my car slightly drifting out of a turn where I hit some gravel in the road and the back end went out a good 15-20 degrees then came back in smoothly with out the traction control ever engaging. I am sure that I would have spun out had I been carrying more speed.
