“.. turning the ignition off simply shuts the engine down ... something that is inherently obvious to me.”
Gotta be careful with that though. One notch too far and the steering wheel is locked.
If I was worried about my safety, I’d sacrifice the engine.
Is it possible he thought he wouldn’t be able to “control the car” if it were in neutral. One can still steer in neutral, though. Maybe he wasn’t thinking...
There is NO key ignition in Prius.