What about him?
If you start eliminating cases because of the age-bias, and the number of cases falls very low relative to the millions of cars on the road, you are faced with the distinct possibility that there is no systematic failure.
Every physical system is subject to breakdowns. Memory chips and microprocessors can fail. They WILL fail. Some percentage of such failures could lead to runaway acceleration.
If the number of such failures falls well below the rate of people being hit by lightning, then the economics of the situation may well argue for doing nothing. It may be that multiply-redundant fail-safe features could improve the failure rate, but the price of such a system would insure that few purchased it.
I’m not saying that Prius has A problem but I think that Toyota’s problem is the computer and not the gas pedal!