When loads shift.
Along with the pilot, the loadmaster is the most important person in the safety of a cargo airplane. Here's why.
When a heavy load such as 5 military vehicles totaling 70,000 lbs, shifts to the tail end of the plane during ascent, the nose pitches up. A stall occurs. This is a good time to deploy a parachute, if you have one. If you don't, then it's a good time to spend the remaining 5 seconds of your life remembering the good times. I don't think that there's any way out of this.
The dashcam video was caught next to an airport in Afghanistan. The driver sounds British, when he cusses briefly. Interestingly, he seems to have a dog with him in the cab of the truck that he's driving.