Reuters: Asiana passenger reportedly opens A321 emergency exit during approach

[DaveReidUK]

Well yes, it's true that Airbus refer to those (and the entry doors, come to that) as "plug" doors.

Everyone I've met in my career has called them "semi-plug" - the difference being that they are held in place, not by the shape of the door and the hole (i.e. like a bathplug) but by stops built into the door frame. The clue is whether the door has to move inwards (at least initially) in order to open it or whether, as with the Airbus narrow-bodies, it simply moves up to clear the stops and then outward (as per the diagram).

The important factor in this instance is how much (or little) resistance cabin pressure would put in the way of the door opening on final approach.