2006 Nissan Xterra transmission problems

Dt*: the contact stated while driving 20 MPH down a sloped driveway, the vehicle stalled. As a result, the brakes and power steering system failed. The dashboard lights illuminated while the vehicle was descending. The contact attempted to put the vehicle in park, but there was a grinding noise. The vehicle was shifted back to drive. The parking brake was engaged but there was no tension. The vehicle rolled to a stop. The dealership inspected the vehicle, but was unable to determine a problem.

I own a 2006 nissan xterra and the clutch failed at 23,000 miles. I recently had it repaired at my expense since it is considered a wearable part and not covered under warranty. The old clutch is in my possession. I am having a hard time believing this part failed due to my driving behavior. I travel mostly over flat lands, do not down shift to slow the vehicle, do not haul loads.