IMO the proper way to evaluate these scenarios is not based on 'what valid reasons a user has', but rather based on safety.

If a key fails, or the antenna/sensor system fails, and somehow senses the 'key has left' the car should NOT be disabled.

Or someone inadvertantly departs w the key in there pocket or purse.

Or a kid tosses the key.


Something as simple as couple gets in car, start, drive to store. Wife jumps out to do some shopping, hubby goes to park. Doesn't realize he didn't have his key. Car stops in the road.