Side/window Air Bag problems of the 1998 BMW Z3

1998 BMW Z3 roadster - there was a spontaneous deployment of both driver and passenger side air bags. While driving on a dry rough road the air bags deployed, consumer did not come in contact with anything, and was driving only about 5 mph when the air bags deployed. Was able to pull over to the side of the road. The vehicle was taken to a dealership, and they say that an impact with a pot hole caused air bag deployment. Consumer claimed he did not hit a pot hole hard enough to cause this deployment. The dealership did not check the sensors to see if there was a problem with the air bags. There was no recall on the air bag defect on this model. However there was a recall on air bags in other BMW models.