If you get on a map which is being closed via a taxi (lfg or invite), you do not see the timer when it will close.
So you might get teleported away from the map without any knowledge that the map will be closed soon. Just happened to me while doing the dwayna pre events
The timer when a map closes must be visible even if you enter the map after the timer started.
One of my 30 accounts (Malediktus.9250).