13 Tahoe curtain bags deployed

[Vernski]

My step daughter bought it a few months ago it only has 5844 on it. When she was driving it she says that she was pulled off the road by the tires and hit a rock puncturing the tire. The tire had to be replaced but the rim was not hurt. In this process all the curtain air bags deployed plus the shoulder bags in both front seats. If it hit hard enough to set these off how come the dash bags did not deploy? She was the only one in the vehicle so why should both sides all deploy? I was wondering if anyone else has had this experience out there Thanks...Vernski