If this is the only possible way to secure the classroom door, ok then. But if the door has a lock on it and the outside lever is locked during an active assailant event, this method will not only mostly-unlatch the door, the force of someone trying to enter the room could pop the inside lever off. Let’s do a better job of planning for an active-shooter incident. Teachers should not have to resort to this.
Thanks to Chuck Park for the video link!