We've heard about several incidents where for whatever reason pilots have lost control of their Mavics.. have the advertised dual sensors helped in any of these situations and how would we know if they had?

When you do a calibration, are you calibrating both sensors or just the primary?

The Mavic Pro has five cameras it uses to 'see' and map a complex 3D environment in real-time during each flight. DJI calls this FlightAutonomy and allows the drone to avoid obstacles when in intelligent flight modes. The 24 computing cores and multi-core vision sensing engine by Movidius in it's micro-processor help to make all of this possible.

As far as I'm aware, you're just supposed to do a compass calibration at each new location or before each flight. Only one IMU calibration is needed until the DJI Go specifically asks you to calibrate the IMUs. It's all pretty much fool-proof. The Mavic Pro does all of the work, you simply navigate with the controls and control the camera.