I just tested this once and for all.
Got into the car, closed the door, and pressed LOCK on the keyfob.
There is good news and bad news.
The good news is that even when i lock the door, it is still possible to open the door from the inside, pulling twice....Pull-release-pull (Works on both front and rear doors, so nobody should be trapped inside)
The bad news is that when you lock the door, you arm the alarm, so anyone left in the car, that tries to get out, will trigger the alarm, and the person with the key has probably left so no way to turn the alarm off.