Instead of insisting that a prosecution go ahead, the airline needs to ask how long it took for the person at check in to report the 'threat' to how long it took security to respond.
Or maybe the magistrate whose time will be wasted could ask these questions prior to throwing it out on the grounds it is vexatious.
The miscreant has already learned a lesson in that she was offloaded - probably feeling quite humiliated in the process - and no doubt has run up some legal costs plus the cost of alternative transport home.