Side/rear Glass problems of the 2011 Hyundai Sonata

Today I was driving down the road at a normal speed when I heard a loud bang. It was so frightening I thought I had been shot. I was starring straight ahead. There was no truck in front of me. I was on a two lane road divided with a grass medium with steel grids separating the sides. I immediately stopped the car to find out that the glass of the moon roof had shattered and had completely come out leaving a hole in the center of the roof. Fortunately, my inside visor was closed and the glass did not enter the car. The temperature had gone down to a chilly 60 degrees that night and warmed up during the day. I searched the area and found nothing to indicate a rock or an object having hit the glass. There was a hole in the middle of the roof. I called insurance and Hyundai dealership because the car is still under warranty. Immediately the Hyundai representative said something hit the car pointing to a spot that had residue wax from a recent waxing stating this is where the hit had come from. I disagreed and insurance is now sending an adjustor.