Assuming the pax in question ran forward they would have encountered the senior cabin crew member anyway. Most of the BACX senior crew members are fairly worldy wise in my experience. Fair enough BACX have some junior guys down the back, but everyone has to start somewhere. They fluff their lines occasionally on the PA which gives us chance to have a little titter, but im my experience the senior guys at the front know what they're doing. On the whole I feel a lot more reassured by the BACX crews that I do with a lot of other airlines so I think we should give em a break.
The trouble with having some random pax stand up and start yelling FIRE! is that is tends to just cause panic. Once the whole plane starts panicking events kind of take control of themselves. It's hard to stop 80+ people trying to jump up once they've got themselves all excited. I've been sat next to people in the past who have thought that engines were on fire because they can see smoke coming from the breather masts. The answer is obvious.... paint over the windows so the pax can't see the big whizzy things and gag them so they can't make silly noises!!