Dangerous GPS jamming?

No.
He needs to be able to recognize when the system is being jammed and how to work around it.
The fail safe for the pilot navigation system is that the GPS feed into the INS exceeds the kalman filter limits and is disregarded. However, there are weapons that rely on GPS for terminal guidance. the pilot has to learn and adapt by making realtime in the air decisions and act.

I agree that as the FAA moves toward relying more and more on ADS-B, which requires WAAS data quality, the GPS recievers have to be more secure to reject any jamming inputs. Jamming can introduce false data into the GPS navigator, or totally block the signal.

BT