2003 Z71 - Took out keys, car still running??

2,500 miles Silverado Z-71 - Today, I put the ignition in the stop position, took out the keys and the engine was still idling running. Received a message - "Service 4WD", the emergency brake and ABS lights were on and I could not shift out of park. I put the keys back in the ignition and tried to toggle with the ignition - nothing. Finally, after 5 minutes the engine died. I restarted the engine and everything was fine. Poltergeist or do we have a problem?

Update - Shop replaced the ingition switch - said there was a short in it.......