Several things went well for me in this.
- My pickup did not flip over. I like the visibility of riding higher than in a car, but it does add to the risk of a rollover.
- No other cars were particularly close to me, so no other vehicles were involved in the accident at all.
- There was no damage to the truck or injury to me.
- The accident left me completely off the road, not partly on the road where other cars might hit me.
I must thank the anonymous local good Samaritans who checked to make sure I was OK and who found and returned my suitcase. I had not realized that my luggage had been thrown out of my camper shell, but it had popped the locked door of the camper open without difficulty.
In retrospect it's not that hard to see how this happened. In the spin, my truck would have probably taken about 2 seconds to make a complete rotation around its center of mass. The tailgate was probably about 4 meters behind the truck's center of mass, which means the centrifugal (pseudo-) force on the suitcase would have been about 4 times its weight. I have a tendency to over-pack, so my suitcase probably weighed about 40 lbs. The resulting 160 lbs of force at the base of the camper shell door was easily enough to pop it open.
One last thing. I was wearing my Miraculous Medal when this happened. I will make sure to wear it more regularly now -- especially when travelling!