4Runner auto locks doors when sitting in car after turning off ignition

Occasionally I find myself in a situation where I sit in the car after turning off the ignition. After a couple of minutes, the doors lock. Then when I try to get out by opening the door, the honking alarm goes off.

This conditions for this triggering this alarm, known as the door-ajar alarm on the Internet, are described in the owner's manual and are intended to thwart thieves. Opening the door from inside when the alarm is set triggers the alarms. A possible scenario is that someone breaks into the car by breaking a window and then tries to open a door while still standing outside, then the alarm goes off.

According to the owner's manual, locking the doors with the key fob is the way the alarm gets set. There is no mention of just sitting in the car after one turns off the ignition. I'm looking for the rational for this event.

Thus far I've only thought of the situation where a thief is hiding in the car that the driver is not aware of while he drives. Then the driver parks, gets out, doesn't lock the doors, the thief sits in the car for a while, the doors auto lock, then the thief can't get out. Does that make sense?

 

It must be a Toyota thing, my Sequoia is like that too.

 

Great question OP @Manzano Jack
Thanks a million good sir @Borracho Loco
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