I think F3G makes sense. If I have not explained the situation well enough, and all he has understood was there was a problem with the cargo door, then he should ask further if he feels unsafe. Hopefully the CC can then pass on his concerns to me which would prompt a more informative PA. If he then chooses to deplane.....his choice.
What I can't stand are the pillocks who try to cause a scene, and then be leader of the gang. Had one the other day. Humid day, aircon on and the usual condensation dripping down. This idiot gets out his camera and starts taking pictures claiming that this is unusual and unsafe. The CM asks him what the problem is, only to then relay to me that he is an airport egineer (whatever that may be!) which clearly qualifies him to then say that there is a problem with the pressure of the aircraft (we are on stand with outflow valves open and doors open!). I begrudgingly asked the engineer to go and tell this idiot that all is ok (more for the benefit of the passengers around him who may have become anxious).