Locked my keys in S60 2004 with engine running. Any ideas?

This is how it happened and I cant figure out why:

I have an S60 2.5T 2004. I opened all the doors and was vaccuming the
car when I noticed the front tire flat. I started the engine (all doors
still wide open/ajar) to plug a pump into the cig lighter to see if I
can fill it up.

About 10 mins later I removed the pump (damn thing didnt work), and
went around shutting the doors (engine still running) so I can get the
spare out of trunk. As soon as I shut the all doors and the drivers
side, i notice all doors were latched down and couldnt get in my car.
Trunk was also locked. My car still running.

I got my spare key delivered and got in. I called dealer and they said
there was one more incident reported elsewhere but they didnt know if
there was a defect they could reproduce.

I tried reproducing the problem but couldnt. Does anyone have any ideas
how this could have happened? Any one else with this problem?

Thanks