Was 2002 exploder drive by wire? was it shift by wire? If it wasn't shift by wire then it is very unlikely that there was anything stopping him shifteing into neutral. And I refuse to believe that the ignition key was disabled.
Up until recently you could shift our trans into reverse at 80 kph(or faster probably) if you so desired, which can be an amusing party trick when done right.
I am pretty certain that Explorer uses a mechanical shift linkage and a conventional ignition switch. I want to take this young man's story at face value but it's difficult. It's certainly possible that the ignition switch and shifter could fail at the same time but in listening to the audio that is available, I strongly suspect they did not fail. I suspect this young man did not know how to use them. I could certainly be wrong.
I gathered the impression that neither the driver nor the police operator/dispatcher have a useful conception of what makes an automobile go/not go. I was struck with how the ignition switch and gear selector were bruited as possibilities as though they were buttons one might try on a kitchen appliance -- push that one and see what it does. Maybe there is more audio we haven't heard that proves me wrong about this... I hope so.