I find it a bit shocking they'd be caught by surprise by a planned GPS outage. The exercise happened as intended, and all aircraft in the affected areas should have received warnings BEFORE they even took off. These are not drug smugglers - they filed a flight plan before leaving the ground.
The automated weather service was also out. This made it difficult or impossible to use the ILS because they can't set the local altimeter. This was a swiss cheese chain of events. It was a moonless dark night so the mountains weren't visible.