Carrier/rack problems of the 2015 Mercedes Benz GLK350

My wife was driving on the interstate at ~65mph in her new 2015 Glk350 w/ panoramic & 4matic & ~7000 miles. It was 7:00pm in very light traffic. No one was near her at the time of incident. She heard a very loud starling bang. At first she thought a tire had blown. She then heard faint crackling noise above her head. The sun shade was closed so no glass dropped into the cabin area. Within minutes she noticed that the sunroof had shattered. Noteworthy point, the sunroof glass was broken convex. So, it was slightly pouched upward, which we thought was unusual. I taped the sunroof and brought it to the local dealer the next day. The dealer said she hit something and that's what caused the issue. I mentioned that their was no one else around and their were lots of internet reports with similar problems. He said you can find anything on the internet. My cost to replace sunroof was $2500 using my insurance, or $1500 with a discount if I was paying for it myself. I'm not sure why there was 2 different prices. After researching the safercar. Gov site, I found approx. 9 cases of late model mercedes with a very similar issues. There's also numerous articles and news stories including other car manufacturers on the net with the same sunroof issues. There is a safety issue here.