Side/window Air Bag problems of the 2011 Volkswagen Jetta

Driving on the interstate I came to the end of some scarified pavement. When I went across the end of the scarified pavement, the right side airbags went off. The dealer inspects under the car and finds a small scratch on the trailing arm mount and says the car was bottomed. Only problem is the scratch is not on the bottom of the mount and is even above the parking brake cable which routes beneath the mount. The parking brake cable does not have any damage or scratches on it. Also, why wouldn’t the front airbags go off instead of the side? if the car had bottomed on the pavement or on the lip of the pavement where the scarified pavement ended, the mark on the trailing arm mount would have damage from the initial point of contact and scrape along the leading edge of the mount until whatever hit it had cleared under the mount and it would have looked a lot worse. Anyway the dealer wants $4000 to fix the airbags, not including a new seat cover since they don’t manufacture it anymore. If you want a picture of the impact mark let me know. It’s very miniscule. Also, after the airbag deployment, there were not any tire, rim, or alignment problems. In comparison, in my 1997 golf, my son hit a bad pothole last spring that popped the tire, bent the alloy rim, and whacked the alignment but the airbag did not go off. If you need any other information feel free to contact me.