This happened to me back in Sept '13. I turned my car on and closed the door while the engine was running. Went inside the house to get something, when I came back, the doors were locked. Both windows were up (since it was the first time turning the car 'ON' that day). It was a first for me. I've always turned ON my car and would let it warm up while I would go back inside the house (for what ever reason). This was the first time it did it and I still don't know why. I now roll down the window before I close the driver side door (and if I have to go back inside the house). I don't know....
No Brand loyalty; my loyalty is to my money!