A roll-away is a serious matter and is always the fault of the driver.
But I'm going to take a jab at UPS here. Does the fact that were are driving equipment that our competitors junked over a decade ago factor into our safety picture (hello, anti-lock brakes) ? Seriously, I can't think of one reason why every UPS driver is not driving a low-step, automatic transmission, power-steering vehicle.
If our entire fleet consisted of these vehicles, UPS would see a reduction in roll-aways, shoulder injuries, knee injuries, and slips-and falls (from on-off vehicle). Just my opinion.
Brownie