It sounds like the departure time was "corrected" for what ever reason. The most normal is that the cabin doors were originally closed at 1300 and brakes released causing a departure. Then the doors were opened again for whatever reason, and closed again with a second departure at 1340.

This is quite common in a delay situation. The pilots and flight attendants want the first departure recorded because then they start getting paid.

p.s. if you are getting $250.00 an hour the 40 minutes buys a beer or two.

[This message has been edited by exAC (edited 12-30-2001).]