It's like that on Mitsubishi Outlander Phev.
There is a separate Park button, and I think there is no risk of confusion. I have actually occasionally powered down the car when I just wanted to put it in park, but there is no real danger in that.
It automatically engages "Park" when powering down, but not when exiting the car, but maybe it should as long as the car is not moving when the door is opened.
Actually, as the car is aware of that no one is sitting in the drivers seat, it would be trivial for Mitsubishi to program it to prevent the car from moving, or at least starting to move from a stand still using the ordinary brakes.
I guess that would be true for all cars with airbags, which would be every car sold, at least in in USA and EU.
Maybe it should be mandatory.