It's a Ford Mondeo. We borrowed it from the MIL. On both occasions we've parked outside the house and made sure the car was locked etc. When we've gone out the next morning all four windows have been down. MIL says it has never happened outside her house.
if it is the global opening then you must be opening the car from a distance and giving a bit of time before you reach it. The windows dont open that quickly and i sure youd catch them moving if you were close.
check if you have global opening / closing by holiding down the unlock button for a few seconds when you open it.