A neighbor had an explorer a few years ago that went from park to drive all by itself in a grocery store parking lot and slammed head on against a wall before she could get it stopped.
If there had been someone standing in front of that vehicle they more than likely woulda been run over. SMH
There are two reasons why I always set the parking brake.
1)To prevent things like that from happening
2)I live in a state with an annual safety inspection and they check that the parking brake works. If it’s never used it may seize up and need a repair to pass.