You're not going mad
@Wills. This has happened to me three times. Definitely not accidentally pressing the buttons after it has been locked. The first time i thought it was my fault but the next two times was in a multi storey. One long press to double lock and fold mirrors. Watch the mirrors fold up,walk away. Come back to find windows down by a third. Rang my local dealer to get their opinion. The specialist window coming down on its own accord engineer was on lunch break. They said he would ring me back when he gets back . That was in February. Hasn't happened since, so haven't tried to contact him again. Didn't want to interrupt his lunch.